Exclusive to Newgrounds is the Creature from the Black Lagoon intro. As far as these intros go, I think this is the last one. You can see the other two in Vamp'd, and IS2BU:Halloween Episode.

Girl With Hook 4 Hand: La Llorona, in the first episode, the little girl with a missing hand is taking a shortcut through a nearby river alone after a long night of trick or treating. Her mom has warned her to not wander alone by the river, especially after dark. It is told that a mourning, lost soul haunts the river at night searching for the children she drowned, but whatever you do, DON'T LOOK HER IN THE EYES! The villagers fear of turning to stone if you look into her eyes. You have been warned.