Stretch is a fictional character from the Casper the Friendly Ghost series of comic books, (although he and The Ghostly Trio, his brothers, were also known as Fatso, Fusso and Lazo in the comics), cartoon shows, and films.
Stretch hates 'fleshies', the term ghosts use for humans, and really dislikes Harvey's daughter, Kat. At first, Stretch dislikes Dr. Harvey as well, and he and his brothers form up embarrassing plans to try and get rid of him and his daughter. For instance, Stretch tells Dr. Harvey he knows his wife, Amelia, and that they will find her in the Afterlife and bring her to him, if he keeps Carrigan away from the house. He agrees to the deal, and Stretch tells Fatso to go find her; However, when Dr. Harvey goes to greet his wife, it turns out to be Fatso dressed in drag, implying that maybe the deal was a joke.
Eventually however, he and his brothers grow to like Dr. Harvey and while out drinking at a bar, Stretch sees that Dr. Harvey isn't as dry or as proper as he makes himself out to be. He and the other two concoct a plan to murder Harvey, so that he would become a ghost too. However, Dr. Harvey tells the Trio they are his best friends and he loves them, so the three ghosts change their mind. However, as he's backing out of the bar, dancing, the doc falls into an open trench and dies, becoming a ghost. He returns home to his daughter, and to Stretch's pleasure, he doesn't recognize Kat. But due to a gesture they shared as daughter and father, which happens to be a pinky swear, her father remembers who he is, and again Stretch's plan fails.
After the final battle with Dibs and a then-incorporeal Carrigan, Dr. Harvey had indeed kept his word and gotten rid of the greedy woman, so Stretch and his brothers shockingly keep their prior promise and bring his wife to see him. Amber, a classmate whom had antagonized Kat earlier in the film, tries to break into Whipstaff Manor with Vic while the party is taking place, and plan to ruin the party, but the Ghostly Trio scare her and Vic out of the house, but not before they panic and run through the party area, startling the guests a little bit, who then assume it was planned by Kat as part of the entertainment. After the party, Stretch and his brothers form a band to play the end credits song 'Casper the Friendly Ghost', with Stretch playing lead with an Electric Guitar.