Here's Ollie! / Save the Visitor!

S2 E22: Ollie invites the Wonder Pets to his warren for a sleepover.  Though Ming-Ming is reluctant, Linny persuades them that it will be fun to spend the night underground.  Ollie is thrilled!  He proudly leads the Wonder Pets down a tunnel and soon they are introduced to an amazing world of subterranean chambers and creatures.  They meet Ollie's family and are particularly impressed by Ollie's intelligent little sister, Olive.  Ollie is so excited to have the Wonder Pets sleep over that he cannot fall asleep.  The Wonder Pets use teamwork to help Ollie count sheep--they dress up as the sheep--and soon Ollie falls asleep.  And snores. Tuck wakes up in the middle of the night and finds a visitor in the classroom—an extra terrestrial!  The Wonder Pets form a bond with their new friend, who must return home soon, or be stuck on earth forever.