Aluminoid
Aluminoid is a person(s)that converge on events surrounding a major sporting event. Aluminoids will at all cost seek out and retrieve any left behind can(s) or bottle(s) with "deposit" marked on them. The only bottle or can that is safe are those in ones hand. Those left on the ground, a table, trash can or on the bumper of a car are fair game. After feeding on cans and bottles, they converge in mass on the local bottle or can return venue. They are particularly active around major college football venues before and after a game.
The Aluminoid's arrived at the tailgate party grabbing all the cans on the ground then proclaim "any cans?" before leaving to feast on the next location.