The Bloodmoon Altar

The Bloodmoon Altar enters tapped.
{t}, Add two mana of any color in any
combination of colors to your mana pool.
Whenever a creature enters the battlefield under
your control, add a mana of any color to your
mana pool.
"Apathy is death. Watching what I have seen come
to pass... and not choosing to act? That is apathy."
— Grimlore