When Bart flying at class, the swoop appear in many buildings.
Appearances
Opening Sequence — At the beginning
HD Opening Sequence — At the beginning
Gallery
Appearance in the early Season 1 opening.
Appearance in the Season 2 opening
The HD Opening Sequence appearance
The Christmas Opening Sequence appearance.
The callback opening from "He Loves to Fly and He D'ohs"
The live-action opening