Many people don't know that this is the second book in the series and would assume that the Tale of Benjamin Bunny would be, but this is not true. Squirrel Nutkin has been named as second.
This is the story about a cheeky little squirrel named Nutkin. When all the busy little squirrels sail across the lake to Owl Island to collect nuts, Nutkin plays about and teases Old Mr. Brown, the owl who gives the squirrels permission to hunt for nuts on his island in return for little gifts they bring. Nutkin teases him terribly until Mr. Brown suddenly grabs hold of him and tries to eat him. Nutkin gets away but leaves his beautiful tail behind. Ever after he is a squirrel without riddles and jokes who knows when to keep his mouth shut.