Glueboy is a fictional animal character in the Hey Arnold! TV Series.
He is a mule that was purchased by Ernie Potts, Mr. Hyunh, and Oskar Kokoshka. They each pooled $200 to buy him because they were led to believe it was a racing horse.
In "The Racing Mule", Glueboy, with Arnold as his jockey, won the grand prize of $3000 in the mule race at Santa Conchita.