Sven and his cousin Ren first knew one another from their days as pups laying in a whelping box together. Upon seperation, Sven ended up growing up in Germany while Ren grew up in America. Some years later Ren is finally reunited with Sven when he invited him over to stay with Stimpy in America. Ren who is filled with ignorance believed that Sven is as intelligent as he is. Only to discover that his own cousin has developed stupidity over the years. Stimpy got along with Sven really well during his first meeting with the German chihuahua. Putting up with Stimpy's own stupidity was enough for Ren, but to have two Stimpys' around the house made matters worse for Ren.
Sven Hoek originated from the TV show the comic book is based off of and was voiced by Billy West. He only appeared in two episodes, one which is focused on him and the other he merely appears as a background character. He's received more appearances in the comic book series than he did in the TV series.