Rivia, the Strider

Hexproof
{w}: Put a 3/3 white elemental with hexproof and lifelink onto the battlefield.
{u}: Put a 4/4 blue elemental with flying onto the battlefield.
{r}{r}{r}: Put an 8/8 red elemental with trample and haste onto the battlefield.
{b}{b}: Put target creature from a graveyard onto the battlefield under your control.