Christopher P. Walberg (born April 2nd, 1986) is a former child actor and musician was known for his voice as Stinky Peterson for almost every episode (except for Downtown as Fruits). He was around 9 years old at the start of the series.
He played the role of "Timmy Moore" in "Little Giants" (1994) and appeared in an episode of "Frasier" (1993), credited as "Boy". 
Here's a post made by user "Josh Croft" on the IMDb board that gives an updated status on Walberg's life:
I am friends with Christopher "Topher" Walberg here in Nashville, TN. He is the bassist and vocalist in an incredible rock band called "H-Beam". They are quickly becoming one of the most entertaining local rock bands here in Nashville. Little do people know that Nashville has a spectacular underground rock scene. Bands like "The Loft", "Folk Medicine", "Mile 8", and "Old Union" join "H-Beam" in this soon to be very recognizable area for great ecclectic rock bands."
Topher's sly skillz on the bass makes H-Beam's smooth grooves and rockin beats very jammable. Joining Topher in "H-Beam" is his older brother Matt "Hollywood" Walberg who plays guitar and vocals, and Aaron Faust on drums and vocals. Visit www.h-beamlive.com to check out their website."
Topher is a cool cat and a good friend. He's come a long way from "The Little Giants" and will go much further and faster by the path he is taking now. It's awesome to see someone I know very well listed here and to know that he is really a cool down-to-earth dude that loves to rock."
- JCRO (President and CEO)
- JCRODUCTIONS ENTERTAINMENT
- Murfreesboro, TN 
- https://www.youtube.com/user/hbeamlive (Channel URL)