- “Duhhh...he is ole, you are Sven. He is ole, you are Sven...”
- ―Sven introducing himself.
Like all Hoeks, Sven is a Chihuahua. However, unlike his scrawny cousin, Sven is obese, the same size and shape as Stimpy and is also as thick as he is. He's also chubby and friendly, and the moment he met Stimpy, the two became good friends and he even showed him some stuff he had taken with him in his large suitcase and referred to him as his new friend and 'Brother Stimpy.' Ren had known Sven since they were both newborn puppies still in the whelping box together, and Ren apparently hasn't seen him since then. He is shown to have a tiny brain much smaller than Stimpy's, which he was able to easily get out with a pair of tweezers.
Unlike his aggressive and ill tempered cousin, Sven's personality is pretty much Stimpy's in disguise. He's dimwitted, innocent, friendly and good natured, but also fears his cousin when he's starting to get mad. According to Ren, he used to be intelligent in the past, as Ren was waiting to talk to somebody as intelligent as him.
Sven first made his appearance in Sven Hoek in season 2, which would be his only major appearance. In this episode, Ren is annoyed by Stimpy's constant stupidity and can't wait for Sven to come and visit, who he hasn't seen in years, as he wants to have an intellectual conversation. When Sven arrives, Ren is shocked to find that Sven and Stimpy are kindred spirits, having majority of the same interests and hobbies, along with being lodge brothers, belonging to The Loyal Order of Stupids. Ren goes off to get them drinks and tells Stimpy to help Sven unpack, which leads the pair begin to bond, showing each other many of their favored possessions, such as Stimpy's Magic Nose Goblins and Sven's ball of Band-Aids, and each other's brains. Some time later, Ren goes off to work and tells the pair to behave, but they soon break this rule. They begin to play games, such as seek-and-hide and circus. Soon, they get bored and cannot go outside, as it is rainy, so to cheer them up, Stimpy suggests that they play Don't Whiz on the Electric Fence. Ren comes home to find that in their mayhem, Stimpy and Sven have destroyed or vandalized his prized possessions, covering his opera records in bubble gum, opening and 'violating' his collection of rare, incurable diseases, and painting his dinosaur droppings like Easter eggs. This leads Ren to having a breakdown, yelling at them. However, Ren soon calms down and describes in detail how he plans to get his revenge, which includes tearing their lips out, gouging out their eyes, tearing out their arms, punching them, and laughing. However, Ren decides to go urinate before acting on these threats, angrily walking away and coming upon the board game. Ren decides to get revenge on them by peeing on the board, unaware of the game's purpose. Their house soon explodes and they are sent to Hell.
Afterwards, Sven would only make short appearances or cameos.
He made a cameo appearance in the season 3 episode Jerry the Bellybutton Elf, where he is seen as a background character, happily dancing with Mrs. Buttloaves at Ren's party, which included other supporting characters.
He then made one last cameo in Hard Times for Haggis, seen watching Ren and Stimpy in a crowd when Haggis is out looking for his fans.
- It is possible that Sven could hail from a Scandinavian country due to his accent and clothes. It is also possible that he could be from Germany or some country that speaks German, as he often peppers his speech with German words.
- Sven is shown to have several similarities to Stimpy, shown during his debut episode, such as interests and habits. Sven and Stimpy share the same basic character design and the same voice actor, with both being voiced by Billy West.
- According to a deleted scene from the "Sven Hoek" pencil test, Sven was aware of Stimpy's Magic Nose Goblins before he saw them, as he is thrilled that he can 'finally get a good look at them.'