Officer Eugene Switzer is the tertiary antagonist (but not a villain) of the television series' episode "Free Nelly." He is an animal control officer who counts Nelly's being free and Charlie and Itchy riding on her as going against animal codes.
When he is going after Nelly to retrieve her, he ends up teaming up with Colonel Dijon and his helpers, and the former claims that Nelly was insane. They go after Nelly even after Charlie uses the miracle dog tag to turn her invisible and take her into a big store.
Eventually, however, when Charlie and Itchy expose the video, Officer Switzer and his fellow officers have the three circus workers arrested and then comforts Nellie by telling her she is under protection of animal control.
After this is over, one thing is wrong: Officer Switzer exposes the unintended video of Charlie doing an unintentional clown act.
It is unknown who did his voice.