Based on the 2001 version. The 1999 version has never been released on home video on any market.
An archaeological party explore some caverns underground. Dr. Campbell and Dr. Hughes are the two leaders of the archaeological expedition, and get separated. While Dr. Hughes finds an alien corpse with a fossilized diamond, Campbell finds hieroglyphics at the cost of the party except for Hughes and himself. Years later, an alien mothership arrives near Earth’s orbit, which is quickly detected by the military.
Bud Black, a cameraman, learns from a colleague about a dinosaur dig, led by Campbell along with his assistant Holly. Dr. Hughes shows up at the dig site to warn Campbell but is quickly removed from the site. Subsequently, the alien ship sends beams to the dig site to surface more bones of the dinosaur but at the cost of some of the workers’ lives. Holly confronts Campbell about the mysterious deaths and quits after Campbell refuses to launch an investigation. Dr. Hughes manages to find Holly and reveals to her about the legend of Yonggary, the diamond, the alien fossil, and additional hieroglyphics.
She dismisses his claims at first but comes around after he shows her classified data concerning the fossil. They return to the dig site to stop Campbell but arrive too late when the alien ship sends one final beam that fully resurrects Yonggary, killing Campbell in the process. The alien ship dematerializes Yonggary and Dr. Hughes and Holly are taken into custody by the military, where Hughes reveals to Holly that he was taken by an organization and declared to be legally dead so his discoveries can be studied.
Yonggary is then teleported right before them and manage to escape before a helicopter squadron engage Yonggary in battle, only to be defeated. The government then sends Mills, an agent to inform the military of what they had learned from Dr. Hughes discoveries. Mills opts to have the aliens captured but the military wishes to destroy them instead. Yonggary is then teleported to a major city and goes on a rampage.
Holly and Dr. Hughes arrive at the base, only to be confronted by Mills. Mills is then arrested for trying to steal Dr. Hughes’ disc containing new hieroglyphics. As the military continues fighting Yonggary, Dr. Hughes decodes the new hieroglyphics and learns that the aliens are controlling Yonggary via a diamond on his forehead and that another “great light will emerge to do battle”.
The military manages to successfully break the aliens’ control over Yonggary and the aliens send a new monster, Cycor, to battle Yonggary. Cycor initially gets the upper hand but Yonggary emerges victorious in the end, forcing the aliens to flee. The following morning, the military transports Yonggary from the city to a deserted island.Richard B. Livingston as Dr. Campbell
Harrison Young as Dr. Hughes
Briant Wells as Parker
Brad Sergi as Bud Black
Donna Phillipson as Holly Davis
Wiley Picket as Lt. O'Neil
Dan Cashman as General Murdock
Dennis Howard as General Thomas
Matt Landers as General Howell
Bruce Cornwell as Mr. Mills
In addition to receiving financial support from the Hyundai Capital Corp. and Korean Technology Finance Corp., the film received financial and technical support from the Korean federal government by allowing the filmmakers access to military bases, hardware, and locations such as the Historic War Museum in Seoul, a location where filming has never been permitted before. The film was deemed the most expensive South Korean film at the time.
After the film's successful opening, the filmmakers decided to expand the film with additional CG effects, new sets, an expanded story and additional characters, and began reshooting in December 1999. This version would later be released in early 2001 as Yonggary: 2001 Upgrade Edition and as Reptilian for its North American home video release.
Yonggary was released in South Korea on July 17, 1999. The film opened at the Korean Culture Center in Seoul, the first time a film premiered at the center, and sold one million admissions during its opening weekend.
The film was later re-released with updated special effects and an altered story as Yonggary: 2001 Upgrade Edition, however, the re-release was a critical and commercial flop. The 2001 version was re-titled as Reptilian for its North American home video release.
The film was released on DVD by Columbia Tristar on August 21, 2001 as Reptilian, marking the film's only North American home video release to date. Sony Pictures later released the film on VHS on March 5, 2002.
Chuck Arrington from DVD Talk gave the film a mixed review, criticizing the film's acting and dialogue, calling it "painful". But also wrote that the film was funny enough to merit renting it. StompTokyo.com gave the film a negative review, criticizing the film's poor quality special effects, calling it "cartoonish".