"Piglet's Monster Under the Bed" is the second segment of the fifty-first episode of My Friends Tigger & Pooh.
One night, not long before Piglet's bedtime, Rabbit tells him "Don't let the nighty night monster bite." It's just a silly saying and Rabbit tells him so, but Piglet becomes convinced that there's a real monster under his bed. He calls for the Super Sleuths, who agree to help him out, even though they're sure there's no such thing as monsters. Then, everyone gets scared and begins to think that there is really a monster under Piglet's bed.