KARR (Peter Cullen) later (Paul Frees) is the prototype version of KITT, originally designed by Wilton Knight and built by his company Knight Industries. Upon completion of the vehicle, KARR's CPU was installed and activated. However, a programming error made the computer unstable and potentially dangerous. The project was put on hold and KARR was placed in storage until a solution could be found.
Unlike KITT, whose primary directive is to protect human life, KARR was programmed for self-preservation, making him a ruthless and unpredictable threat. He does not appear as streetwise as KITT, being very naive and inexperienced and having a childlike perception of the world. This has occasionally allowed people to take advantage of his remarkable capabilities for their own gain; however, due to his ruthless nature he sometimes uses people's weaknesses and greed as a way to manipulate them for his own goals. Despite this, he does ultimately consider himself superior (always referring to KITT as "the inferior production line model") as well as unstoppable, and due to his programming the villains don't usually get very far. KARR demonstrates a complete lack of respect or loyalty - on one occasion ejecting his passenger to reduce weight and increase his chances of escape.
KARR first appeared in the Season One episode "Trust Doesn't Rust" aired on NBC on November 19, 1982, where he seemingly met his demise at the end. However, he was so popular with viewers that he was brought back again in the Season Three episode "K.I.T.T. vs. K.A.R.R.", for a second time which aired on NBC on November 4, 1984 and then brought back in 2009 for Knight to King's Pawn in season 1 of the new Knight Rider series of 2008-2009 for a third time (marking him as one of the very few villains in the original series and the new series to make a return appearance).
KARR 1.0 (1982-1984)
KARR 2.0 (2008-2009)
Once KITT was constructed, it was presumed that his prototype KARR (voiced by Peter Cullen) had been deactivated and dismantled. However, the latter did not occur and KARR was placed in storage and forgotten following the death of Wilton Knight. When two thieves, Tony (Michael MacRae) and The Rev (William Sanderson), break into the warehouse where KARR - who is entirely identical to KITT with the exception of the Yellow/Green Voice Module on his dashboard - is "sleeping", they unwittingly reactivate him, and he escapes.
When the two thieves realize how useful the vehicle could be, they use KARR to go on a crime spree, whilst Michael and KITT frantically try to catch up with KARR and stop him before anyone is seriously hurt. Bonnie devises a high-powered laser, the only known way to stop KARR, which must be fired from KITT directly into KARR's scanner. However, when KARR needs maintenance, Tony kidnaps Bonnie before the laser can fully be calibrated. Although Michael rescues Bonnie, she is unable to get a clear shot at KARR with the laser and he escapes.
KARR's only weakness is his primary directive of self-preservation and Michael uses this to his advantage. When KARR threatens to destroy KITT in a head-on collision, Michael plays chicken with him, on a hunch that KARR will veer out of KITT's path in order to protect himself. KARR indeed swerves out of the way, but unable to stop in time: he drives off a cliff and seemingly explodes in the ocean (using footage of the climactic scene from the 1977 film The Car, footage that was also used for KITT on a couple of other occasions).
Trust Doesn't Rust was also printed in book form, written by Roger Hill and Glen A. Larson, following the story and general script of the original television episode, expanding some areas of the plot and adding several extra secondary characters.
KARR (now voiced by Paul Frees) was only believed to have been destroyed. He was damaged and ended up buried in the sand on the beach below the cliffs. When the tide had gone out, a young couple, John and Mandy, stumble upon the partially buried car, dig him out, and reactivate him. This time, KARR is furious and has only one clear motive: revenge against Michael and KITT.
KARR is still damaged after the last encounter with KITT and forces John to serve as his driver, and also to carry out some cosmetic modifications to his paintwork to 100% Differ Against KITT in a ravine. KARR challenges Michael and KITT to a final showdown. After releasing the young couple, KARR fires a stolen laser and damages KITT. However, Michael and KITT destroy KARR's laser by reflecting the beam back to the emitter. Damaged, KARR prepares for another attack. KITT and KARR both turbo boost and collide in mid-air. KARR is blown to pieces, but Michael and KITT survive the impact. At the end of the episode, however, KARR's motherboard — i.e. KARR himself — can be seen lying undamaged on the ground amongst the wreckage, its LED's still blinking - suggesting to the viewer that KARR is still "alive".
Originally, KARR appeared identical to KITT and was originally 100% all Black like KITT with a red light scan bar like KITT, and the only physical difference was a greenish-yellow LED voice modulator on his dash (for the first half of the first season, KITT's voice modulator is a red square that blinks on and off as he talks; KARR's voice modulator is the prototype to the one seen on KITT from the mid first season onwards, after it was received well by viewers) and the only other difference was the evil voice. When KARR returns in "K.I.T.T. vs. K.A.R.R.", KARR's scan bar is now amber/yellow and is now very similar to KITT and is still 100% all Black like KITT for the first half of KITT vs KARR until he alters his look later on.
KARR later gets a Black and Silver two-tone paint job incorporating a silver lower body into his familiar 100% all-black finish. KARR's scanner originally made a low droning noise, but in the comeback episode it sounds similar to KITT's but with a slight reverb audio effect added to it. The sound of KARR's engine, originally sounding rough and "fierce", here sounds similar to KITT's, again effected by a reverb. In "Trust Doesn't Rust," KARR had no license plates. In KARR's second appearance, he had a California license plate that read "KARR." Despite various other changes, KARR's dashboard remains correct with continuity – he still has the earlier version of the dash as previously seen on KITT in season 1-2, whereas by the time of 'KITT Vs KARR', Bonnie had updated KITT's dash and various functions at the start of the third season.
When KARR returns in 2009 for his third appearance in Knight to King's Pawn he is once again similar to KITT and is once again 100% all Black like KITT. KARR is now a 2009 Ford Mustang GT 500 KR, like KITT 3000; the only difference is that he has a Yellow Scan Light Bar. In the original series it was more Amber/Yellow, and KARR's voice module originally yellow-green in the original series. It is now 100% Yellow Color and KARR's Scanner sounds much lower with much more of an echo. The sound is especially noticeable when KARR is chasing down KITT while he is still in Ford Mustang Mode.
KARR's personality is also somewhat different in the comeback episode. His childlike perceptions are diminished into a more devious personality, completely cold and bent on revenge. His self-preservation directive is no longer in play. When KARR is close to exploding after receiving severe damage; he willingly turbo-jumps into a mid-air collision with KITT, hoping that his own destruction would also spell his counterpart's. Even KARR's modus operandi is different; serviceful enough in the first episode, he aims to actually make use of other people, anyone, to serve his own needs. One explanation of this change could be as a result of the damage he received after falling over the cliff at the end of "Trust Doesn't Rust", causing further malfunctions in his programming. Indeed, KITT himself is seen to malfunction and suffer change of personality as a result of damage in several other episodes.
In "Trust Doesn't Rust" and the 2008-2009 series, the voice of KARR was provided by voice actor Peter Cullen, better known as the voice of Optimus Prime in the Transformers cartoon series, and whom had a previous working relationship with series creator Glen A. Larson after voicing several Cylon characters in the original Battlestar Galactica. In "K.I.T.T. vs K.A.R.R.", KARR was now voiced by Paul Frees, best known as the voice of Boris Badenov in the popular series The Rocky and Bullwinkle Show and as the voice of Ludwig Von Drake in the popular anthology series, Walt Disney's Wonderful World of Color. As with William Daniels, the voice of KITT, who was never credited on-screen, Frees was uncredited on-screen for his role, leading Cullen to sometimes be mistakenly credited as providing KARR's voice in "K.I.T.T. vs K.A.R.R." Peter Cullen reprised his role as the voice of KARR in the 2009 Knight Rider episode, "Knight to King's Pawn."
KARR 2.0 (Peter Cullen) is mentioned in the new Knight Rider series episode "Knight of the Living Dead", and is said to be a prototype of KITT (Knight Industries Three Thousand). The new KARR acronym was changed to "Knight Auto-cybernetic Roving Robotic-exoskeleton" K.A.C.R.R.E Instead of an automobile, a schematic display shows a heavily armed humanoid-looking robot with wheeled legs that converts into an ambiguous off-road vehicle. When KARR finally appears in the episode "Knight to King's Pawn", he takes a form once again similar to KITT as a 2008 Ford Shelby Mustang GT500KR, but has a yellow scanner and 100% yellow color voice module and is once again 100% All Black like KITT. once again Similar to the original character, this entirely different "KARR" project (2.0) had an AI that was programmed for self-preservation, and he was deactivated and placed in storage after he reprogrammed himself and killed seven people.
In the episode, a spy infiltrates the SSC and activates a self-destruct program within KITT, placed there secretly by Dr. Graiman. In order to save KITT's operating system (which is given priority over his memories), Michael and Sarah transmit the files to the back-up computer at the headquarters, but the transmission is also intercepted by an unknown third party. It is stated that KITT, KARR and the base back-up computer are the only systems able to run the program, and leaves Dr. Graiman with only one conclusion: KARR 2.0 is still out there, and someone is trying to reactivate him.
KARR returns in the episode "Knight to King's Pawn", with Peter Cullen reprising his vocal role. A pre-recorded message from Dr. Graiman reveals that Mike was KARR's driver and his memories were erased after KARR became uncontrollable. He says that he knew of and opposed Alex Torres and the NSA's plans to reactivate KARR, as they wrongfully believe KITT's artificial intelligence will overwrite KARR's programming flaws. During the dismantling of the SSC (FLAG's control centre), KITT's A.I. chip is removed and delivered by Torres to the NSA, where it is installed into KARR. Mike vows to end this once and for all, and infiltrates Area 51 to rescue KITT, using another chip built by Billy. KARR activates himself, viewing the re-activated KITT as a threat that must be terminated. Alex states that he is now in charge and KARR must take his orders; KARR agrees, but then merges Alex with him as a driver to seek out Mike.
KARR seems to believe that it is his destiny to merge with Mike as before, and comes after KITT to destroy him and get Mike back. Despite KITT lacking his transformation protocols and weapons, Mike takes him into battle anyway. Using a grappling hook, Mike and KITT pull out KARR's chest plate, freeing Alex, and Turbo Boost through his body, destroying him in a manner similar to the destruction of KARR in the original series. Given the short nature of the battle and the ambiguity of KARR's fate, it is possible that the new KARR might return yet again, although in the following episode entitled "Exit Light, Enter Knight" Mike is told that the KARR project has been permanently abandoned. Strangely, despite KARR's acronym being "Knight Auto-Cybernetic Roving Robotic-Exoskeleton" K.A.C.R.R.E in "Knight of the Living Dead", and "Knight to King's Pawn" Billy refers to him using the original "Knight Automated Roving Robot" KARR.
KARR is once again similar to KITT, also a 2009 Ford Mustang Shelby GT500KR based on the Knight 3000 and is once again 100% all Black like KITT The main difference is that KARR has a yellow scanner (in the original series it was more amber) and the scanner noise is lower in sound with more of an echo. The sound difference is especially notable when KITT is racing toward KARR while KARR is still in Mustang mode and KARR's Voice Module originally Yellow/Green is now 100% Yellow Color.
KARR is in both Knight Rider: The Game and its sequel. In the first one he is teamed with Garthe Knight, but at the end of the game is caught in an explosion and falls into the sea. In the second he is again teamed with Garthe; however, KITT damages his systems and drives him into a fire. In the sequel, he is once again teamed with Garthe, as he didn't abandon him like the Foundation did. Garthe outfitted KARR with new weapons and copied his processor for an army of robotic enemies, culminating in a rocket armed with a laser that could kill thousands.
Mattel has released two die-cast metal models of KARR. A 1:18 scale model as part of the Hot Wheels Elite collection and a 1:64 scale model as part of the Hot Wheels Retro Nostalgia Entertainment collection. They both resemble KARR's appearance from KITT Vs. KARR with silver paint around the bottom half of the vehicle. The small one however lacks the amber scanner light and instead retains the red scanner from KARR's appearance in Trust Doesn't Rust and there is also a KITT which is completely identical to KARR in his first episode in Trust Doesn't Rust.