Badgermole Cub by paying ({1} magic symbol) ({G} magic symbol) , When it enters, its first ability triggers, earthbending a land that can produce at least ({U} magic symbol) .
Cast
Freed from the Real by paying its mana cost, attaching it to the earthbent land.
Activate the land by tapping it, adding at least ({U} magic symbol) .
Badgermole Cub's second ability triggers, adding ({G} magic symbol) .
Activate
Freed from the Real by paying ({U} magic symbol) , untapping the land.
Repeat from step 3.
Notes
If the land adds more than one mana on its own, then you may also get other types and/or colors of mana as a result of this combo.