Petrified Elder

Reach
Creatures with flying or reach get +0/+1.
{b}{g}: Regenerate Petrified Elder. If it regenerates this way, transform it.
{t}: Add {r}{r}{r}{r}{r}{r}{r}{r}{r}{r}{r}{r}. This mana can only be spent to activate legendary creature abilities. Petrified Elder loses this ability.