Twitch is a tall light green fish who has blonde messy hair. He wears green shorts and a necklace with a tooth on the end of it. He sometimes has severe neck twitches, which is how he got his nickname.
His name might have inspired the live streaming platform called "Twitch.tv." However, his first appearance was made before that website was made.
In "Bulletin Board," SpongeBob refers to Twitch as "Surfer Fish."