Charlie Sheen -- My Kids Are in Danger ... My Ex Brooke Mueller is an Evil Whore

Charlie Sheen says his ex-wife Brooke Mueller is a dangerous, EVIL whore who's putting their twin boys in SERIOUS DANGER ... and now, Charlie says he's on a mission to stop her before it's too late.

Sheen just called TMZ and told us ... his 4-and-a-half year old twin boys Bob and Max have already suffered physical and emotional damage from the time they've spent in Brooke's care. In fact, he says they're very close to getting kicked out of school.

Charlie says the boys are deathly afraid of Brooke's house -- which is covered in pet lizards, various insects and other critters -- and they suffer night terrors after spending time at the home.

Charlie also says Bob suffered a bad rash on his face after recently spending time with Brooke -- a rash that "looked like somebody burned him."

Charlie says he's complained to L.A. Child Services -- but they refuse to help. Instead, Charlie claims, Brooke is getting MORE custody ... and he doesn't understand why.

Sheen ripped Child Services on a Twitter rant last night -- calling them "doosh bags" who have done nothing to protect his children. He also called Brooke an "evil and pathetic über loser" and a "whore."

Sheen says Brooke is supposed to get her first unsupervised overnight visit with the twins tonight -- and Charlie says he's very afraid of what could happen.

Charlie says he's not sure if Brooke is back on drugs, but he is sure about one thing -- "She's as awful a parent and a person as you can possibly draw up."