Beginning as a character-layout and cleanup artist on The Simpsons in the early 1990s, Anthony “Tony” Bell established his animation credentials by working on episodes such as “Bart’s Friend Falls in Love” and “Krusty Gets Busted.” He moved into directing with Nickelodeon’s Rugrats, overseeing numerous episodes and the TV movies Rugrats Vacation and All Growed Up, and later contributed episodes to…