Heal

 is an active ability, which means it will only activate once the creature has a full bloodlust counter.  For a list of all Cards with this ability, click here! 

Variations
can appear as certain activation, or with a chance to activate. It can activate on Entering Play, on leaving play, or during the card's turn. It can target itself, one, several or all of your creatures, and it may target a specific race. The heal amount can go from 1 to 6. There are special abilities for Healing on Attack and Healing on being attacked, as well as an ability that heals your Vampire Lord.

Strategy
Heal works well on creatures with lots of Health, and even better on creatures with the Brothers in Arms ability !