In Super Mario 64, during the first mission of Jolly Roger Bay, Unagi the Eel blocks the entrance to the sunken ship. No matter how long you stay near him, he will not leave until you swim away and come back. This is because the game is trying to hide that he has no animation for exiting the ship; instead he simply warps out once Mario is far away. It’s possible to see this in action by swimming away and holding C-Up so the camera moves above Mario.