Every family has its "crazy uncle"; the Cleavers have Uncle Billy. An eccentric personality worthy of any picaresque character in literature, Uncle Billy (actually Wally and Beaver's great-uncle) boasts of exotic hunting exploits that never occurred, makes extravagant promises, and hands out bills of money like donuts. He is a high roller, a teller of tall tales and an all-around phoney - but a lovable phoney as played by colorful, gravel-voiced Edgar Buchanan. Beaver is enchanted by this figure, as any boy would be. But, in a poignant ending, he must experience the disillusionment of learning - the hard way - what sort of person Uncle Billy really is.
This is one of the truly great "Beavers," a near-serious drama to rival the third-season episode "Beaver and Andy." It shows Beaver traveling a trajectory from innocence to experience and wisdom, by way of an emotional crisis: discovering Billy's true nature at a hotel barber shop. "Uncle Billy" shows Beaver and Wally having to deal with an adult who is like a child in many ways. Ward and June are wary of the influence Uncle Billy might have on the boys, but at the same time want them to respect an elder relative; this is the central conflict.
Uncle Billy returned for a sequel episode in the final season ("Uncle Billy's Visit"); in that episode he is less of a rogue and more of an indulgent relative.