The Great Book of Grudges

Whenever a dwarf creature you control dies,
put a grudge counter on the Great Book of Grudges.
{t}{r}{w}, Spend X grudge counters: Create X
2/1 red Dwarf Berserker creature tokens.
{t}{3}{r}{w}, Spend 20 grudge counters: All creatures gain +4/+0 and
trample until the end of turn.