Gil has had the most appearances as a main character (followed by Molly).
Gil is the only guppy who appears in every pop song.
Gil is the only one out of the guppies who screams (though Molly has screamed a couple of times).
Gil is often the target of the jokes in his and Molly's sketches, usually being chased away by an animal or the Little Fish and sometimes is gullible for doing anything else. Gil just has bad luck (sometimes).
Gil's favorite color is purple.
Gil may have feelings for Molly.
Gil's lunch box is the same color pattern on his tail, but it is blue instead of green.
Gil has done a lunch joke, he has done only 1 lunch joke. He has done one in Call a Clambulance!.
Gil is the only guppy with a one-syllable name (despite the two-syllable name Molly calls him, "Gilly").
Gil is ticklish.
Gil (along with Molly and Bubble Puppy) is often used to represent the show on merchandise and other things.