The Ultimate Behemoth is a type of RV similar to that of a double-decker bus, but the steering wheel is on the top floor. It features a big screen TV, its own satellite, an elevator, 4 deep fryers (one for each part of the chicken), along with various other features (including a horn sounding very similar to a ship's foghorn). It was being sold at Bob's RV Round-Up. Homer and the children were impressed, but Marge worried the expensive price on the RV.
Homer wanted to buy the impressive RV in an attempt to stay ahead of Flanders, despite Marge's warning not to because the family can't afford it. While working out a price deal with Cowboy Bob in his office, a dismayed Homer finds out that he had been rejected due to his poor credit rating. It turns out that the Ultimate Behemoth is way out of Homer's price range and he's only qualified for a dilapidated RV which further disgusts the rest of the Simpsons, hoping he'd have the common sense to walk away without one.