Prince Frederic von Anhalt's Plastic Surgery -- Zsa Zsa Gabor's Husband’s Face is Vucked!

Zsa Zsa Gabor's husband Prince Frederic von Anhalt says a plastic surgeon botched a routine operation on his face ... and now he's left looking like a mutated German version of Professor X.

Prince tells us he went in for cosmetic surgery Monday but the procedure went horribly awry ... and now the 70-year-old wants to take legal action.

A-hole's lawyer wouldn't get specific on the procedure -- but we're told he'll file suit if the damage is not reversible