Corrected entry: During the Robot Devil's song, he tears off Bender's right arm and throws him through a hole in the floor. When Bender lands, he has both of his arms. (00:17:30)
Corrected entry: When Fry and Leela go into Robot Hell, Nibbler leads the way. But when Bender rescues them and they fly away with him and his angel wings, Nibbler is not there - They've forgotten him. However, sure enough, he's back next episode.
Correction: That vast, tardis-like abdomen of Bender can produce anything he likes, from chilled beer to popcorn. It's a toilet, a home for a small child, a huge gold depository, and Fry fits in there without discomfort. He's got a spare arm or two in there. No big deal.