Tree Warp is a major glitch that warps you to the last underworld location you entered.
It is an application of Dynamic Sprite Spawn Overflow, described on the vanilla wiki, where loading the three sprites that constitute the pink tree with a face overflows the intended maximum number of sprites.
Tree Warp brings you to the inside of the most recent entrance you used with a falling animation. As a side effect, it re-closes all the chests on the supertile it takes you to. This makes the glitch useful for duplicating items. (A consequence of this is that it trivializes any No Logic Triforce Hunt, without additional rules.)
If you tree warp to an EG2 tile (a small underworld location with one exit), you should save and quit from there. If you walk out the door, the game will freeze for up to 18 minutes while it tries to restore you to the location you entered from.
This guide shows one of the easier setups for Tree Warp. (The video on the vanilla wiki shows an older, less reliable setup.) The outline is:
- Have at least 6 arrows, 6 bombs, and 6 rupees so that the thief is guaranteed to spawn 6 sprites when it hits you
- Enter Village of Outcasts from the top center, making sure that the northern pink tree is loaded
- Get a thief and two cucco skeletons to a particular area, and make sure the spear-throwing moblin isn't there
- Let the thief bonk you to the right, which spawns 6 sprites and knocks you to a location where a second pink tree is visible, causing Tree Warp
If you get a tree warp setup slightly wrong, so that the number of sprites on screen is off by one, turn around and leave the tile the way you came. If you continue with the tree warp with the wrong number of sprites, the game will crash.