Omnath, Locus of Nothingness

Landfall — add 1 mana of any color
{g}: add 2 mana of any color other than green
{1}{r}: deal damage to any creature equal to the number of elementals you control
{2}{u}: look at the top card of your library, if its an elemental you may cast it for {3} less
{3}{w}: until the end of turn this creature gains lifelink and +1/+1 for each elemental you control
{4}{b}: sacrifice a creature, you don't unspent mana