The List

Forbidding Watchtower

Forbidding Watchtower enters tapped.
{T}: Add {W}.
{1}{W}: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.

Duel Decks: Mirrodin Pure vs. New Phyrexia

Tenth Edition

Forbidding Watchtower comes into play tapped.
{T}: Add {W} to your mana pool.
{1}{W}: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.

Urza's Legacy

Forbidding Watchtower comes into play tapped.
oc
T: Add one white mana to your mana pool.
o1oo
W Forbidding Watchtower becomes a 1/5 white creature until end of turn. This creature still counts as a land.