Because of a bad upbringing, Gamzee is always stoned on sopor slime, a substance not supposed to be eaten because it supposedly affects the troll's minds, and is a sort of juggalo/ clown cultist. While high, he is very mellow, goofy and friendly and nothing angers him.
SPOILERS: Further along during the story, he runs out of sopor slime and suffers an extreme faith crisis along with finding his crush dead. Now sober and completely insane, he believes it is his highborn duty to kill the other trolls, strangling Equius Zahhak and beating Nepeta Leijon to death with juggling clubs. He only stops his murderous attacks because of a major shooshpap from his friend Karkat.
Gamzee was named after forumite Gammy, as well as "Gamze", which is a Turkish word meaning "dimple" or "coquettish look". Makara is the Sanskrit counterpart to the Capricorn sign, as well as referring to a mythological Hindu creature with the hind legs of an aquatic creature and the forelegs of a terrestrial one (much like the Greek Capricorn).
In text, Gamzee speaks with aLtErNaTiNg CaPs. When sober, he randomly switches between all lowercase and ALL UPPERCASE LETTERS AND STILL HONKS from time to time.
Stoned: YoU jUsT gOt To Be GoInG wItH wHaT fEeLs RiGhT aT wHeRe YoUr HeArT's Up In, YoU kNoW?
Sober: WELCOME TO THE DARK CARNIVAL, BROTHER. honk. HONK. honk. HOOOOOOOOOOONK.