Enrage

 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 often only targets a specific race. The rage can be increased by usually 1 or 2, in rare cases by 3.

There is a variation of Enrage for every Damage School, which increase all damage dealt from that school, including abilities like Fireball.

Strategy
Enrage works well on creatures with the Brothers in Arms ability !