On a recent visit to Prince Rupert, my granddaughter and I encountered a Pacific banana slug (Ariolimax columbianus) slowly moving along a walking trail. This is a large (up to 10 inches long) native slug typically found in coastal B.C. forests west of the mountains.
It was a brownish-yellow colour, but they can be bright yellow (hence banana), greenish or reddish-brown, or even white.