A Washington state man was arrested this week for sexually assaulting a beaver, which had been laying in the road — dying — after getting run over by a car, a report says.

Richard Delp, 35, was taken into custody on Monday night not long after the alleged incident in Columbia Park, according to KVEW.

A witness told the station that she caught Delp in the act while attempting to rescue his furry victim.

She said she saw the beaver get nailed by a vehicle, and was on her way back to the scene with a container to put it in.

When she got back 30 minutes later, Delp was on top of the mortally wounded critter — pants unzipped with a pocket full of meth, according to police.

The woman called 911 and officers eventually showed up to arrest Delp. He was later charged with animal cruelty and possession of methamphetamine. The beaver did not survive.