Narkeplam, Nature's heart

Double Strike, Hexproof, Vigilance, Trample.
Whenever Narkeplam deals combat damage to a player, add that much mana of any combination of colours to your mana pool at the beginning of your next main phase.
{t}, Move a +1/+1 counter from another creature you control onto Narkeplam, then gain 3 life. That creature gains Hexproof until end of turn.