Despawning and Respawning Glitch
The Waterbortion Glitch is a glitch in Chip's Challenge 2. It results in entities starting on a particular turtle disappearing if the level is reset while something is spring mined off that turtle.
It can be seen in this example gif, wherein Chip spring mines a block off a turtle and resets the level after dying from doing so. The eye is only included for visibility.
See also this gif, which demonstrates that the object doing the pushing does not need to be the player as long as you restart at the right time:
This also works when the entity that is spring mined off the turtle does not match the entity at the start of the level: