In Shrek 2, Gingy and Shrek had a plan and went to the Muffin Man, who made Mongo in order to help Shrek, Donkey, Puss, and the others to enter the Far Far Away castle. Mongo is first seen crushing an ice cream cart under his foot. He then destroys a billboard sign that has a picture of fairy godmother. He quickly gets distracted by a giant Farbuck's Coffee cup for display on top of the Farbucks building before he realizes there is nothing in it, so he discards it. Donkey (as a horse) convinces Mongo to follow him to Far Far Away's castle. Mongo and the team begin to storm the castle. Mongo is angered when a catapult's flaming shot hits his upper gumdrop button, knocking it off of him, to which he kicks the burning gumdrop, destroying the catapult. When he tries to bring down the bridge, the guards attempt to break him and get rid of him for good by soaking him with hot foamy milk. Mongo is able to resist one soak, but his arms break on the second soak, causing him to fall in the moat. Gingy (who was with Shrek on Mongo's shoulder) jumps down onto him, while Mongo's severed arms keep the bridge open long enough for Shrek to successfully enter the castle. The latter takes out the guards and lowers the bridge as Puss lifts Gingy with his sword and is caught by Pinocchio, who bawls over leaving Mongo to sink in the moat leading to his death.
While Donkey and Puss are singing (after Shrek and Fiona turn back into ogres and after Fairy Godmother died), Mongo also sang along (while in the moat). He sung "Livin La Vida Loca" along with the rest of the gang. It is unknown what happened to him after this, but he most likely remained sunken in the moat.
Mongo reappears in Thriller Night rising from the graveyard as a zombie during Shrek's dream. He begins to dance with the other zombies in the film until Shrek wakes up.
Video Game Appearances
Mongo appears in Shrek Super Slam as a stage. Battles are fought on a giant birthday cake he carries.
Mongo makes a cameo on the Suburbs of Far Far Away track from Shrek Smash and Crash Racing. He walks around the track and if any careless racer makes contact with him, their kart will spin out. Mongo also appeared in Shrek pinball in the Shrek plug and play TV game.
The roar Mongo makes when he loses his gumdrop button is similar to that of Godzilla.