Prince Frederic von Anhalt's Plastic Surgery -- Zsa Zsa Gabor's Husba

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

Anhalt moans, "They made me look like a monster!!"

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