Level: Pipistrellos Cave
Items needed: Boomerang, Giraffy (if you have him)
What you do is once you first enter the cave, you will have to fight off two waves of gel things that fall from the cieling of the cave. Once you beat the second one continue onward to the bat boss. Once you are free to move again run backwards to the very back, upper left corner. Charge your boomerang until the boss is almost in the front of you. Then, release the boomerang and it should get stuck on his back. Just sit and block from the same spot now until the boss is killed. If this glitch doesnt work you must remove the patch. Check "How to Remove Patch"