Someone cut off the head of a sea lion in Northern California and rode off with it in a bag. Authorities are now offering $20,000 for information that helps find the perpetrator.

The suspect was seen using an 8-inch black knife to remove the sea lion’s head, placing it in a clear plastic bag, and riding away, authorities said.

The National Oceanic and Atmospheric Administration’s Office of Law Enforcement said a witness reported seeing a person decapitate the dead animal before leaving the area.