Aisaka said:
I can't think of anyting that I believed right now, but once I did convince my friend that there was an animal named "Drop Bears" Then hide up in tree's and jump down on people, crush their skulls and then eat all their brains.
And the only way to repel them is to pour urine over yourself.
You mean kinda like this?
http://www.absoluteastronomy.com/topics/Drop_bear
"A drop bear (or dropbear) is a non-existent Australian marsupial. Drop bears are commonly said to be unusually large, vicious, carnivorous koalas that inhabit treetops and attack their prey by dropping onto their heads from above. They are an example of local lore intended to frighten and confuse outsiders and amuse locals, similar to the jackalope, hoop snake, wild haggis or a snipe hunt.
It is often suggested that doing ridiculous things like having forks in the hair or Vegemite
Vegemite or toothpaste spread behind the ears will deter the creatures."
Surprisingly many people fall for stuff like that. Just be convincing enough and you make almost anyone believe almost anything.