The magma unicorn has to live in boiling hot habitats or it will disintegrate. It also has an interesting  feature which allows it to grow bigger,if its enemy is bigger than them.It breaths furious,scorching fire,which makes him smaller because he’s partly made out of concentrated ,blue fire and it drains his energy.If it has no enemy it will create a rainbow and distract the other unicorns to the buoyant  rainbow and then he will jump out and then kills them.