Super Mario 64 Glitches

Climb Through Objects
This is a trick where Mario pulls himself through the ceiling of two different spots.

One is where right past the second key door. Walk through but instead of going up the stairs, jump up facing and touching the wall to the left and Mario will catch the ceiling and drag himself up through it, landing you past some of the stairs and up above.

The other is where you go to Bomb-Omb Battle Field and proceed to grab hold underneath the first bridge and the climb to the lowest part and release 'A' and Mario climbs through yet again.