Mastdon Migration

Mob 1: (When Mastdon Migration enters the
battlefield, you may search your library for up to one
card named Mastdon Migration, reveal it, and put
it into your hand. Shuffle your library.)
Trong: (Only creatures with Throng may block
Children of Light Battalion alone.)
{s}: Until the end of the turn, Mastdon
Migration gains Trample if it your turn
or Hexproof if it is not.
"The men of the cold lands follow the beasts, and
when the beasts move south so do they"