Warbond Cavalier

Soulbond
Warbond Cavalier can only be paired with a Bear, Beast, Boar, Elk, Griffin, Horse, Pegasus, Spider, or Unicorn.
As long as Warbond Cavalier is paired with another creature, each of those creatures get +1/+1 and must attack or block together. If both creatures are Elementals, they also have trample and "{g}: Regenerate this creature."