An official wording for devour would be nice.  What I presume it does is that when a creature with devour kills another creature, the destroyed creature is removed from the game (or exiled if you play Magic) instead of discarded.  This is most useful against the necromancer and his reanimates, but perhaps it might apply in the future to any creatures that get the cantrip ability.

Remind me again what Growth does.  Is it +1 melee and +3 life?