A search is underway across central Maryland.
Wildlife officials are looking for an ill-tempered alien creature that thrives underwater, and has claws. Strangely, it's also described as being "rusty."
Maryland wildlife officials are searching the Potomac watershed for the rusty crayfish, an import they fear could displace native crayfish.
The Maryland Department of Natural Resources is conducting its third annual crayfish sampling in the watershed.
The rusty crayfish has already been found in some Maryland waterways, including Piney Creek in Carroll County, the Monocacy River in Frederick County and Conowingo Creek in Cecil County, and researchers are looking to see how far it has spread.
The rusty crayfish is native to the Ohio River watershed and is slightly larger and more aggressive than Maryland crayfish.
It was found in southern Pennsylvania more than a decade ago, where scientists believe it was introduced by fishermen emptying bait buckets.