Nightmare has it exactly right. "Shush" is something we say to ask people to stop talking. There's a scene in one of the Austin Powers movies that uses a similar gag. Dr. Evil's son keeps arguing with him, and Dr. Evil's response varies along those lines: "www-dot-shush-dot-com!"
"At one point in the movie Toy Story 3, Buttercup calls Mr. Pricklepants "Baron Von Shush".
what is that supposed to mean??? Who is Baron Von Shush? hat does it mean to call somebody with that name?
I just saw this movie with my kids and If I remember correctly, Mr. Pricklepants is a character who has the demeanor and accent of a Shakespearean actor, so by callling him Baron Von Shush, they're making fun of his pretentiousness by suggesting he's a member of the nobilty. As others have said, "shush" is something you say to quiet someone and in that scene he was constantly shushing everyone.