In "Legend of the Lost Tribe," Rudolph's son Robbie (voice of Ben Stiller) teams up with Vikings to save Santa's sleigh team from reindeer-gone-bad Blitzen (Hugh Grant), who schemes to turn the antlered creatures into an amusement-park attraction. Other voices include...Donner: Britney Spears. Prancer: Brad Garrett. Old Jingle: Jerry Stiller. Santa/Tapir: Jim Belushi. The Vikings: James Woods.