Jello are desserts made with sweetened and flavored gelatin. Their name is derived from the Kraft Foods brand name, Jell-O, but outside the US and Canada these gelatin desserts are known as jelly. As this is a song rather than a food database we'd better add that the best known Jello in music is probably Jello Biafra
, the former lead singer and songwriter for San Francisco punk rock band Dead Kennedys. Coming in second would be the '90s group Green Jello, who had a hit with "Three Little Pigs
" and changed their name at the request of Jell-O's parent company, who didn't want their product associated with the comic-rock group.