Learning about a star of the skies; heavenly dogs on earth; joke’s on ‘Principal’; ‘Pippi’ goes on a rampage.

Charlie is upset that Itchy wants to return to Heaven, so he devises a plan to keep him on Earth on this week’s All Dogs Go To Heaven (KTLA, Sunday at 8:30 a.m.). For ages 4 to 11.

*

A notorious high school prankster recruits an unconventional drifter to pose as a substitute principal at his conservative high school on “Principal Takes a Holiday,” on “The Wonderful World of Disney” (ABC, Sunday at 7 p.m.). The real principal ends up in the hospital after a hysterical reaction to one of the pranks by the prankster, John Scaduto (Zackery Ty Bryan). For the family.

*

Galileo Galilei, the maverick genius astronomer, is assigned to tutor a teenage prince with a “king-sized attitude” in Galileo: On the Shoulders of Giants, on “The Inventors’ Specials” (HBO, Tuesday at 7 p.m.). The young prince becomes the catalyst for Galileo’s invention of the telescope. For ages 10 to 17.

*

Teddy (Anthony Anderson) is kicked off the basketball team when coach Fuller (Reggie Theus) discovers him smoking cigarettes on an episode of Hang Time (NBC, Saturday at 10 a.m.). His friends try to help him kick the habit. For ages 13 to 16.

*

While waiting for her father’s return from a shipwreck, 9-year-old adventurer Pippi turns a Swedish village upside-down on Pippi Longstocking (Disney, Saturday at 7 p.m.). For the family.