Original Raw and Uncut
Two-Headed Starfish
Normal animation in Toonz Premium looks like any cartoon that came out in the early 00's
Does season 5 have different artstyles or not? Well, let's find out...
Big Face Bob (his face takes up most of his body)
His season 3 worried facial expression (Which becomes rare, but can still be seen a few times in season 5 and a couple of early season 6ers. After that his default expression when he's worried starts changing entirely)
Late season 4 design
BuckBob (His buckteeth are unusually big)
Season 5 CheekBob (This mostly appears in the later part of the season. This version of CheekBob has a subtle difference from season 6's in that the cheeks don't obscure his mouth as much)
The artstyles are more subtle than in 4, so they're harder to notice unless you really try to look for them.