Pinchy, a half-orange, half-black lobster was first brought to the New England Aquarium in Boston last year and is now on display.
Split lobsters, with a perfect half-and-half coloration, are extremely rare, only occurring in about one of every 50 or 100 million animals.
And not only does Pinchy -- named for the pet lobster on The Simpsons -- have the perfect Halloween costume, she was found off the coast of Salem, Mass., a town with its own spooky history.
The New England Aquarium is rolling out the orange carpet for Pinchy, who missed last Halloween thanks to a required 30-day quarantine for new creatures brought into their care.
Kids dressed in costumes will get into the aquarium free this weekend to "celebrate looking different," said spokesman Tony LaCasse.
Pinchy will be on display through November 3.