Sins of the Fathers Chapter 9: Tombstone - S3-E9
Trivia: When Spider-Man saves Tombstone from falling into a bubbling vat he jokes about him coming out with "green hair." Clearly that's a joke referencing DC comics' Joker.
Trivia: The song playing on the radio when Rosebud breaks in, 'I'd Take a Bite of the Moon For You,' references the episodes 'Alone Together' and 'Tick Vs. Chairface Chippendale.' The song playing when El Seed breaks into the botanical gardens is a jazzy version of the show's theme song.