Brine Bender

{t}: Add {b} or {g} to your mana pool.
When Brine Bender leaves the battlefield, create a 1/1 Fellra creature token with defender and sacrifice this creature, add
one mana of any colour to your mana pool.
{5}{b}: Brine Bender becomes a 4/4 Spawn creature and loses all abilities until end of
turn.