Doofus, Marker of Territories

First Strike, Indestructible, Menace, Defender
When Doofus, Marker of Territories enters the battlefield, put a "Marked" counter on each of
up to 3 target lands you don't control.
As long as you control Doofus, Marker of Territories, you may, on your turn, {t} lands that
have a Marked counter on them to add {1} to your
mana pool. Those lands only untap during their original owners untap step.