Adam Lambert
as
Emperor Maximus
Anya Taylor-Joy
as
Marla
Daniel Radcliffe
as
Rex Dasher
Ben Diskin
as
Seadog
Adam DeVine
as
Blizzard aka Blizz
Jim Gaffigan
as
Santa Claus
Henry Winkler
as
Smiley
Gabriel Bateman
as
Theo