It is a semi-transparent gelatin cake made to resemble Gary. It contains pink gelatin for his shell, blue for his eye antennas and edges of his body, and green for his eyeballs and stomach. The only difference in appearance between this cake and the real Gary is that it does not contain the spots and spirals on his shell or pupils in the eyes. The plate it is served on is silver and contains decorated pink and orange flowers around the gelatin.
Role in episode
SpongeBob is visiting his grandmother to celebrate her birthday and leaves Patrick in charge of Gary while he is at his grandma's house. Although SpongeBob feels as though he should be the one serving his grandma since it is her birthday, the latter offers him a dessert: a gelatin cake of Gary. This triggers SpongeBob's concern of Gary being endangered, so he uses his grandma's house phone to call Patrick and see if everything is alright.
Because SpongeBob rushes to his grandma's house phone to call Patrick just after being served the cake, he is not shown eating it on-screen.