RHH's photos with the keyword: arion

This is the Black Arion or European Black Slug, an invasive species here in the Pacific Northwest. It was photographed at Goose Rock in Deception Pass State Park at the base of a tree. It was nearly six inches (15 cm) long. The hole on the side is the breathing hole and the "horns" are actually eye stalks. Though a pest I left it to go its way.

Photographed on a Memorial Day hike in the Chuckanuts.

The hole is the breathing hole.