Dear Stump-Solvers, I'd love to find a children's book I read to my kids in the late 80s-early 90s. Here's what I remember: A slug is moving along and ridiculed by a snail, because the slug doesn't have a shell. The slug suffers a loss of confidence and sadly slimes along. I remember the slime to cross hot pavement. SPOILER: Eventually the slug meets another slug and is happy. Thank you!
This sounds like The Slug Who Thought He Was a Snail by Penny Pollock, published in 1980. “When a snail convinces Sam Slug that he is a snail without a house, they begin a futile search for Sam’s lost shell. Includes facts about slugs.”