Yes, he looked terrified of Chomper till Chomper reminded him they met. As I mentioned elsewhere, maybe that first meeting takes place just before The Mysterious Tooth Crisis episode, perhaps. Had the idea before since Threehorn has a cameo in that one, with no Tricia, Tria and Cera are not looking after Tricia, so either it's Guido, or Threehorn let Tricia wonder around on her own with no supervision for a while.
I wonder if Swooper is a bit dirty, understandable living in a cave most of his life, or if he just looks that way from his animation.
This episode has some good spots, funny ones, some touching ones, at least one that I didn't expect to happen when I first saw it.