Trampoline

The Trampoline, also known as the Springboard, is an unused object found in the cap switch stage object table of Super Mario 64. It takes the appearance of 2 checkerboard hexagonal platforms with a middle red segment with various question marks. This middle section is believed to have been the part that would have moved as the player jumped on it. The object has collision, though the model itself does not load properly. It is not functional, as it attempts to call an unused or unfinished function referred to as "DoTrampoline".

The fact that the Trampoline object is in the object table for the cap switch stages implies that it would have been in a cap switch stage, potentially being the potential Yellow Cap Switch stage or the Princess' Secret Slide in a scrapped segment requiring it, which also has the cap switch stage object table. However, this may have been a placeholder object table, and it may have potentially been used elsewhere.

Super Mario 64 Reimplementation
In some personalized copies of Super Mario 64, the Trampoline object is reimplemented by the Personalization A.I. It may appear as it's normal state, simply being collision and an unloaded model, though some have reported a completed version that is fully functional. It can usually be reported in cap switch stages and the Princess' Secret Slide, and oddly can be reported in places where they are useless, potentially due to the A.I. failing to implement it.