Lobo - Jason Momoa

Awesome.

What I've seen him in:
Baywatch
Game of Thrones
Conan the Barbarian


Santa Claus - Michael Chiklis

Santa is the bounty he aims to kill and they have a pretty epic fight.

What I've seen him in:
The Commish
The Shield
Family Guy (voice)
Fantastic 4
Fantastic 4: Rise of the Silver Surfer
Robot Chicken (voice)
No Ordinary Family


Elves - Noah Taylor

Santa's elves guard Santa Claus when Lobo arrives to the North Pole.

What I've seen him in:
Shine
Almost Famous
Lara Croft: Tomb Raider
Vanilla Sky
The Life Aquatic with Steve Zissou
Charlie & the Chocolate Factory


Easter Bunny - Andy Serkis

This little guy is drunk in a bar when he hires Lobo to kill Santa on behalf of the other holiday characters.

What I've seen him in:
Lord of the Rings: Fellowship of the Ring
Lord of the Rings: The Two Towers
King Kong
The Prestige
Flushed Away (voice)
Rise of the Planet of the Apes


Aurifice - Pam Grier

This is a very dark story line that bookends the Lobo Christmas comic.

What I've seen her in:
Bill & Ted's Bogus Journey
Fresh Prince of Bel-Air
Jackie Brown
Jawbreaker
Larry Crowne


Pa - Jeffrey Tambor

They never really gave him a name, so I'm going to just refer to this character as "Pa"

What I've seen him in:
Three's Company (my girlfriend specifically showed me one of the episodes he was in)
Mr. Mom
Bill & Ted's Excellent Adventures (voice)
The Golden Girls
The Larry Sanders Show
Batman (voice)
Dinosaurs (voice)
Muppets from Space
Girl, Interrupted
Malibu's Most Wanted
Eurotrip
Arrested Development
Hellboy
Hellboy II: The Golden Army
Monsters vs. Aliens (voice)
The Hangover
The Invention of Lying
Win Win
Flypaper
Paul
Mr. Popper's Penguins
Lucky