Briar, Warden of Thorns
Essence of Earth and Lightning (You may have Earth and Lightning cards in your deck.)
Whenever an attack action card you control deals damage to an opposing hero, create an Embodiment of Earth token.

This card's text has received errata:
Essence of Earth and Lightning
The first time an attack action card you control deals damage to an opposing hero each turn, create an Embodiment of Earth token.
The second time you play a 'non-attack' action card each turn, create an Embodiment of Lightning token.