That old video reminds me of my favorite D&D moment.
I was allowed to guest DM for the night to help develop my character. The party entered a spirit realm tied to my characters diety and found themselves in a dungeon with several puzzle rooms. As they entered a large room they saw a door with a large face. Above it were the words scrawled in something that looked like blood "The password is duck"
"WHO DISTURBS MY SLUMBER?!?"
The party leader walks up and with a smug look says "Duck!"
"A strange name, what do you need?"
The party all look confused. "We wish to pass!"
"The path can not be opened without the use of the password."
"Uhm... duck?" "Mallard?" "Swan?" The party are all saying any variation of duck they can think of. Then someone says "Maybe we need to duck?" They all crouch down.
"My my, you would make me blush were I not made of stone. There is no need to bow to me, however the password must be used."
They search the room, natural 20 on the check. They see all around the room, torches lighting up on the walls as if trying to guide them. A skeleton in the corner holds a piece of charcoal to the wall and from that point they notice the entirety of the room's walls are not covered in cracks, but instead writings in various sizes. They soon realize the texts all say the same thing. "The password is duck! THE PASSWORD IS DUCK! The PaSSworD IS duCK!"
Confused they returned to the door. "DUCK DUCK DUCK!" Nothing.
"I grow very tired of you lot, may I return to my slumbers soon?"
Suddenly it dawns on one of them. "What would you call a bird who swims in water, has a yellow bill, and webbed feet?"
"Why of course," the door utters "a duck." A blinding flash of light as the face finally splits open, revealing the path before them.