Great Vault! Desperate Survival!! (大金庫！決死のサバイバル！！, Dai Kinko! Kesshi no Sabaibaru!!) is the 100th episode of Urusei Yatsura.
Mendō invited Ataru at his home to show off in order to delineate the differences between them, only for both to get accidentally locked in a giant vault where they slowly go mad as it floods and try to out-survive each other.
- This is the ninth anime exclusive episode.
- This episode aired after the release of the second movie.
- This is the only episode of the series where Lum doesn't appear, though like in all episodes, she appears in the title card.