General
Since he was a boy, SpongeBob has taken the ownership of Gary. Gary is an intelligent, fully domesticated snail. His intelligence shines through in the fact that he has more intelligent solutions to SpongeBob's dilemmas than SpongeBob himself. But Gary is revealed to be a "mutt" in the episode The Great Snail Race. Gary tends to disagree with some of SpongeBob's ideas, and usually makes an effort to warn SpongeBob. Sometimes he finds SpongeBob to be a complete annoyance, as does Squidward Tentacles. This is evidenced in the episode Sleepy Time. In the episode, Squidward says, "Don't we get enough of you during the day?" Gary seems to agree with him. Gary has had many runs away from SpongeBob: Gary ran away from SpongeBob in Have You Seen This Snail? because SpongeBob forgot to feed him. He was then found by an elderly female owner who fed him a lot, and whatever he wanted. It turned out that she had overfed many snails before. Upon seeing fliers that Spongebob made to look for him, he realized that SpongeBob did love him, and so he went back home. In Dumped he seems to like Patrick more than SpongeBob, and SpongeBob is jealous. However, in the end, it was revealed that Gary only wanted the cookie that was in Patrick's pocket, and then he came back to SpongeBob. The episode ends with Patrick crying, "Gary? I thought what we had was special!"
Gary is able to levitate and teleport, as seen in the episode Gary Takes A Bath. This could mean that psychic powers run in the Star family, as Patrick Star also can display psychic ability.
Some of Gary's meows are lower pitched, some are higher pitched; these could possibly indicate that Gary uses different tones of his voice to communicate with SpongeBob, who is able to take more meaning out of these than most Bikini Bottomites. Gary has only been seen speaking English three times. Once in the episode, Sleepy Time but that was only a dream, and once in the episode Secret Box but he only made a, "Eer" sound and then said, "No." The third time was in the SpongeBob movie, when Gary had a pair of bucket helmets on his eyes. He chanted "Meow Plankton" in unison with the other mind controlled sea creatures saying "All hail Plankton".