Synopsis by Hal Erickson
Beaver (Jerry Mathers) trades a glass doorknob with Larry Mondello (Rusty Stevens) in exchange for a stray chihuahua that Larry has found. Dad Ward (Hugh Beaumont) figures that the dog, whom Beav has named Poncho, belongs to someone, and thus places an ad in the paper. Though Beaver and Wally (Tony Dow) try not to get too attached to Poncho, they're fighting a losing battle -- and thus the boys concoct a scheme to hide the pooch when the owner shows up. This episode marks the final series appearance of Diane Brewster as Beaver's teacher Miss Canfield; also, the woman who accepts Ward's classified ad is played by Joanna Lee, the main villainess from the immortal Z-picture Plan 9 From Outer Space, and later an award-winning writer of made-for-TV movies.