It is a pineapple karate-chopped into halves to resemble Gary the Snail. The exterior is used for his body, the pineapple slices are used for his eyes and shell, and the leaves are used for his antennae.
Role in episode
SpongeBob is in his kitchen, karate-chopping a pineapple on the counter into halves. Once it is complete, he gives the fruit to Gary as a gift. Gary, however, does not understand why he made it. SpongeBob tells him that he made it because he is "so sweet" just like pineapples. An unfazed Gary then leaves the room, refusing to eat the fruit.
After being left out for a little while, the pineapple treat attracts flies, one of which flies into SpongeBob's mouth, causing him to choke. Patrick then walks into the kitchen and punches SpongeBob after witnessing him choking, freeing the fly from his mouth.