This list contains combat vehicles which never left the design phase or had an extremely limited production (usually < 10).
Australian Cruiser Tank Mark 3 "Thunderbolt"
Australian Cruiser Tank Mark 4
Rhino Heavy Armoured Car
Australian experimental light tank
Skink anti-aircraft tank
Entwicklung Series Entwicklung series, a comprehensive redesign of German armor from small tracked vehicles to a 100-ton super-heavy tank. Only a single E-100 chassis was completed
Neubaufahrzeug, pre-war heavy tank design, five built
Panther II, development of the Panzerkampfwagen V "Panther". A single chassis was built
Panzerkampfwagen VII "Löwe", a super-heavy tank project that never reached prototype stage
Panzerkampfwagen VIII "Maus", a super-heavy tank. Two prototypes built
Panzerkampfwagen IX & Panzerkampfwagen X Paper project
Landkreuzer P. 1000 Ratte; paper project
Landkreuzer P. 1500 Monster; paper project
12.8 cm Selbstfahrlafette auf VK30.01(H) "Sturer Emil"
Heuschrecke 10, Krupp's design for a new self-propelled artillery gun
VK 4501 (P) - Porsche Tiger tank; one Tiger (P) built
10.5 cm K (gp.Sfl.) Two prototypes built
P43 heavy tank, Fiat Ansaldo's design for a new heavy tank.
P43 Bis heavy tank, Fiat Ansaldo's design for a new heavy tank.
Type 95 Heavy Tank, 4 built in 1934
ATG Carrier So-To. A light armored transport with a AT Gun in Type 97 Te-Ke tankette structure
Type 97 Chi-Ni medium tank
O-I, super-heavy tank design in the 120-ton range. Only one supposedly built
Ji-Ro-Sha 105 mm self-propelled gun on Type 95 Heavy Tank chassis
Hiro-sha 150 mm self-propelled gun on Type 95 Heavy Tank chassis
Type 98 Ta-Se self-propelled anti-aircraft gun
Type 98 20 mm AAG Tank self-propelled anti-aircraft gun
Type 4 Chi-To medium tank; two completed and four chassis
Type 5 Chi-Ri medium tank
Type 5 Ke-Ho light tank
Type 4 Ho-To self-propelled gun on Type 95 Ha-Go light tank chassis
Type 5 Na-To tank destroyer; two built
Type 5 To-Ku amphibious tank
Type 97 Naval 12 cm self-propelled gun
Type 5 Ho-Ru 47 mm self-propelled gun. A light tank destroyer akin to the German Hetzer
Type 5 Ho-Ri tank destroyer with a 105 mm cannon and an additional 37 mm gun; paper project
Ka-To or Ka-To Sha 105 mm SP AT Gun. Ka-To's development was ordered in 1943, but how far it progressed in development is unknown. Ka-To's hull was to be similar to the Type 4 Chi-To or Type 5 Chi-Ri
Poland
4TP (light) tank
10TP tank
TKW (light) tank
PZInż 130 amphibious tank
TKS-D tank destroyer
Mareșal tank destroyer
TACAM T-38
Verdeja
Antonov A-40
T-43
SMK tank
KV-13 Three prototypes built.
T-100 tank
SU-100Y
SU-14
PPG tankette
Object 416
IS-7 Heavy tank
KV-4 Heavy tank
Tank, Heavy, TOG I
Tank Heavy, TOG II
Tank, Heavy Assault, "Excelsior" A33
Tank, Infantry, Valiant (A38)
Tank, Heavy Assault, Tortoise (A39)
Tank, Infantry, Black Prince (A43)
Medium Tank T20
Heavy Tank M6
Assault Tank T14
T95 Super Tank Destroyer
T28 Super Heavy Tank
T29 Heavy Tank
T32 Heavy Tank
T30 Heavy Tank
List of prototype World War II combat vehicles Wikipedia (Text) CC BY-SA