A person who always tell 'great stories' about him / herself where in fact they didn't actually happen OR they actually did but only 1% on the story is true.
A person who always have the same experience as your only that his / her experiences are more "extreme" than yours. So extreme to the point the they are already doubtful.
A 'professional' liar and a deceiver.
Mike: Pfft! That undying draw? In your dreams.
. . .
Trisha: Jeff, I already slept with a Lion!
Jeff: Me too! But with Hyenas too!
Trisha: Wow! That's great! (...undying draw...)
. . .
PSA: Beware of Undying Draws offering you cheap products!