Ex Gomora is a kaiju that only appeared in game "Ultraman Fighting Evolution Rebirth". To unlock Ex Gomora you have to complete Ultra Mode Episode 05.
Ability (Available on the game)
Sharp tail: Ex Gomora can use his tail to kill his enemy with single attack. To use this ability press R1+O/circle button.
In Ultra Mode Episode 02, Ultraman cut Gomora's tail. After Gomora's tail was cutten by Ultraman, He escaped from the battle. Gomora reborn in Ultra Mode episode 05 as Ex Gomora.