Mako, Seaweed Berserker

Trample, Vigilance
Your unspent mana doesn't empty from your
mana pool at the end of your phases or turns.
{t}{x}Tattoos of Fernface:Tap and pay X
where X is the number of creatures you control
to give up to that number of creatures tattoos.
Tattoos are an enchantment that gives the
enchanted creature +2/0, as well as 'When this creature attacks, gain {g}'