Throughout the series' run, he was voiced by at least five different voice actors:
- Christopher J. Castile
- Jarrett Lennon
- Ben Diskin for Seasons 2-4
- Blake McIver Ewing for first movie and Season 5
- Gavin Lewis (who did his voice in the second movie)
Eugene is very well-known for being optimistic in which he always looks at everything on the bright side. He also serves as a jinx, a person who has bad luck and always gets hurt all of the time. His catchphrase is "I'm okay!" after being involved in an accident that he's in.
Eugene and Arnold have been friends since they were in preschool. Arnold has always been looking out for Eugene every time that he's with him in a different situation. Mainly, Arnold is mostly the one who causes Eugene to have bad luck and also to get hurt. But for Eugene, he seems to be pretty okay with it. Everyone including Arnold has shown some respect for him, which makes him feel very comfortable about it.
- His Third Voice Actor, Ben Diskin also voiced Sai from Naruto Shippuden, Shoutmon, Cutemon from Digimon Fusion, Humphrey from Alpha and Omega sequels, Nigel Uno, Hoagie Gilligan from Codename: Kids Next Door, Stitch from Stitch! and Carapace, Pegasus, Nooroo and Sass from Miraculous Ladybug: Tales of Ladybug and Cat Noir.