When Homer inadvertently humiliates Bart in front of a stadium crowd, Marge encourages Homer to enroll in a fathering enrichment class taught by therapist Dr. Zander (guest voice Rudd).

Shocked to learn that Homer often strangles Bart for mischievous behavior, Dr. Zander conducts a series of treatments with the help of Kareem Abdul-Jabbar (guest-voicing as himself) to teach Homer what it feels like to be young and small.
But when Bart learns that the therapy sessions have transformed Homer into a pushover, he takes advantage of Homer and becomes a school bully.

Hoping therapy could also cure Bart of his bullying habits, Marge enlists Dr. Zander’s help to patch their relationship

Source: FOX