(CNN) — The claws came out for a security screening.

Transportation Security Administration agents got a surprise when they stopped an unusual passenger this week at Boston's Logan International Airport: a 20-pound lobster, alive in a checked bag.

TSA spokesman Michael McCarthy tweeted a photo Monday of the absurdly large crustacean in all its shellfish-y glory.

".@TSA officers are skilled at screening all sorts of items in checked baggage...including this 20+ pound lobster at @BostonLogan," he wrote.

Live lobsters on planes are completely fine with the TSA.

"A live lobster is allowed through security and must be transported in a clear, plastic, spill proof container," according to the TSA's online security screening guide . "A TSA officer will visually inspect your lobster at the checkpoint."

It also recommends that travelers contact airlines about their policies on flying with a live lobster before arriving at the airport.

McCarthy told CNN that Monday's lobster was in an insulated cooler, so it was good to go.

Apparently, it's not out of the ordinary for officers to run into a lobster during security screenings, especially in New England.

"What was uncommon on this instance was the size of the crustacean," McCarthy said in an email.

McCarthy added the lobster was "ultimately cleared to continue onto its destination."