The Underminer is a supervillain appearing at the very end of The Incredibles, prompting the Parr family to spring into action and serving to demonstrate that they will go on to have many adventures and fight various enemies as a superhero team. His ambition is to destroy peace and joy. He appears with greater roles in the spinoff video game The Incredibles: Rise of the Underminer and the later Incredibles comics by BOOM! Studios. He is also set to be the opening antagonist in the upcoming sequel Incredibles 2.
Role in the film
The Underminer's motivation is to show his existence.
The Underminer was killed when jumped on top of unfinished head part his robot creation in which he was on top of into his lair which exploded and destroyed his robot army ending his plans.
In the comic series, The Underminer makes an appearance in the "Terror from Beneath" story arc, in which he briefly allies with Dash to fight off alien invaders. However, the appearance is revealed to be part of an extensive hypnosis-induced dream. He later makes an actual appearance as a member of the Unforgivables, the criminal alliance headed by Xerek. As part of a plan to ruin the reputation of the Incredibles, Underminer is given control of a giant robot painted in the Incredibles' colors and rampage through Metroville. Xerek later eliminates Underminer upon completing his purpose.
Some fans speculate that the Underminer is actually Gilbert Huph (or even a possible relative of Huph's) out for revenge, (due to their similar facial features, personalities, height, hate/disregard for all mankind (Bob Parr being no exception) etc.)
Humorously both Huph and the Underminer's respective voice actors both starred in the Toy Story series as Rex and Hamm respectively.
The Underminer's name is most likely based off the now-retired Pro-Wrestler, The Undertaker. Back then, the Undertaker was one of the most popular Pro-Wrestlers.
The Underminer (in keeping with the tradition of having most of the cast be based off of Marvel characters), is likely based on the Mole Man who was the very first known villain of the Fantastic Four.