Mr. Snail is the father of Snail and the husband of Mrs. Snail.
Mr. Snail is never seen in the original Franklin TV series nor any of the Franklin books. He first appears in the Franklin and Friends spinoff series.
Snail mentions his mom and dad in "Franklin Runs Away," stating that it takes them all day just to get to the mailbox and that it would take them forever to get to the tree fort.
Mr. Snail is mentioned indirectly in "Franklin's Advice" when Snail does not want to tell his parents about having cracked his shell in a game of soccer. He eventually admits it to them after Franklin tells him that he will do so otherwise. To his relief, they do not forbid him from playing in the future as he had worried they might, but only until he gets better. In the same story, Snail uses having to help his dad push a pinecone as an an excuse for stopping jump-roping because it his hurting his cracked shell.
In "Franklin and the Shadow Show" from Franklin and Friends, he and Mrs. Snail bring Snail to see Dr. Bear when he has a bad stomachache. She asks if Snail has eaten anything unusual recently, but he has not. With Franklin and Bear's help, they discover that Snail's stomachache is down to him being worried about not yet having a puppet for the shadow show.