Question: do slytherin muggle borns exist?
Answer: Muggle-born Slytherins exist, but are very rare, as noted insultingly by Scabior the Snatcher. There have also been definite examples of half-bloods sorted into the house, including Tom Riddle, Dolores Umbridge, and Severus Snape. ... Also, pure-bloods are not automatically placed in Slytherin.