Wide Wanderer

Trample

Landfall—Whenever a land enters the battlefield
under your control, you may have Wide Wanderer
gain walking for one of the types of mana it can
produce. (For example, if it produces {g} or {u}, you
may have it gain forestwalking or islandwalking).
Then put X +1/+1 counters on Wide Wanderer,
where X is the number of different types of mana
the land can produce. This ability triggers only twice
each turn.