Forbidding Watchtower
Land
Forbidding Watchtower enters tapped.
: Add 
.
: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.
Aleksi Briclot
The List (PLST)
• #10E-352Rulings
Activating the ability that turns it into a creature while it’s already a creature will override any effects that set its power and/or toughness to a specific number. However, any effect that raises or lowers power and/or toughness (such as the effect created by Giant Growth, Glorious Anthem, or a +1/+1 counter) will continue to apply.
(wotc • 2009-10-01)
A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.
(wotc • 2008-08-01)
Rulings
Activating the ability that turns it into a creature while it’s already a creature will override any effects that set its power and/or toughness to a specific number. However, any effect that raises or lowers power and/or toughness (such as the effect created by Giant Growth, Glorious Anthem, or a +1/+1 counter) will continue to apply.
(wotc • 2009-10-01)
A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.
(wotc • 2008-08-01)