CA Banana Slug

Banana slugs are often bright yellow (giving rise to the banana sobriquet) although they may also be green, brown, or white. Some slugs have black spots (Ariolimax columbianus) which may be so extensive as to make the animal look almost solid black.
The Pacific banana slug is the second-largest species of terrestrial slug in the world, growing up to 25 centimetres (9.8 in) long, and weights of 115 grams (4.1 ounces). (The largest slug species is Limax cinereoniger of Europe, which can reach 30 centimetres (12 in) in length.)