Ice
Teh Sexy Monkey Queen
Right, so there could be a 616 version of him running around, or another timeline/universe version accidentally brought in. Or maybe Beast just used the results of his research, which were probably obtained through painful and unethical methods.
Or it could be a horrible continuity error that will never be explained.
Take your pick.
I doubt there's a new Sugar Man because now that means that another mutant created. So really, it's the last one.