From the press release:
HULK SMASH HOLIDAY SEASON!

Celebrate the holiday season with interconnecting Hulk Santa Variant covers from superstar artist Ed McGuinness, exclusively on Hulk #18 and Fall of The Hulks Gamma!
HULK #18 (OCT090512)
HULK #18 MCGUINNESS VARIANT (OCT090513)
HULK #18 MCGUINNESS SANTA VARIANT (SEP098250)
Written by JEPH LOEB
Pencils & Cover by WHILCE PORTACIO
Variant Cover by ED MCGUINNESS
Santa Variant [...]