13 Books Found

Based on your description:

"A horror book or possibly short story in a collection about 20 years ago, so it had to be out in the early 2000s already, about tiny men with wild mane-like hair coming out of tubatures, bathtubs, sink etc. and starting to attack the human protagonists, they had tiny spears that puntured like needles, one of the protagonists ends up committing suicide on a tree."