I'm surprised that you haven't updated the SpongeBob SquarePants page in a long time, there's still about a dozen or so transformations that you didn't capture, and here's some that I remember (I might forget a few like inflations but not all):

"I Was a Teenage Gary": SpongeBob and Squidward are turned into snails. Squidward also gains weight from Gary's food.

"The Curse of Bikini Bottom": SpongeBob and Patrick are turned into ghosts.

"Krabby Patty Creature Feature": Sandy and the townsfolk turn into Krabby Patty monsters.

"Goo Goo Gas": The customers, SpongeBob, Patrick, Mr. Krabs, Squidward and Plankton are turned into babies.

"The Great Patty Caper": A fish turns into a werewolf.

"The Inside Job": Plankton turns into SpongeBob and Patrick.