Ryan "Sumo" Sumouski is one of the three main protagonists (More as a deuteragonist)
in Clarence. He is one of Clarence's friends. He loves to do all sorts of crazy things so that he can enjoy having fun with Clarence, Jeff, and everyone else. Like his friends, he is socially awkward. He was originally voiced by Jason Marsden in the "Pilot," but was replaced by Tom Kenny in the series.
Sumo is a scrappy, streetwise kid who grew up on the right side of the wrong side of the tracks. When problems arise, Sumo's solutions are unorthodox and often messy. A wild card and fearless to a fault, Sumo is unpredictable, independent, and often acts without thinking things all the way through. Sumo is fiercely loyal to his friends, and always available. Jeff and Sumo are polar opposites, but Clarence bridges the gap between them. Sumo is the instinctual third of this trio. However "Chimney" it is shown that he is quite handy as he was able to build a ladder out of sticks and shoe laces.
Sumo used to have long, brassy hair, but asked Clarence to cut it, as heard in the "Pilot." He currently has no hair at all, except for several strands. He has a big forehead, small, and somewhat crooked teeth, with spaces in between some, and has big eyes and big pupils as well. Sumo wears a black t-shirt, cut-off jean shorts, and dark red boots.
In Season 3, he wears a West Aberdale Elementary uniform, which it consists forest green short sleeve shirt and khaki pants, for which Sumo cut them off to match his other clothing.
Jeff - Sumo finds Jeff a bore. Even though they did have fun at Jeff's house when Clarence was away, he still finds him boring. The two of them are friends, but Clarence seems to be the one that glues their friendship together.
In Dream Boat, his last was "Sumozski", but however in "Space Race", it spelled as "Sumouski", while in Sumo Goes West, last name was once again is "Sumowski", although it is unknown if this is a spelling error.
This led to a minor confusion and controversy in regarding to the last name changes, that had affect two other characters, Such as Clarence (who went from Wendell to Wendle) and Jeff (Who went from Randall to Randell).