Wall of Spears

Defender (This creature can't attack.)
First strike

Wooden Sphere

Whenever a player casts a green spell, you may pay {1}. If you do, you gain 1 life.

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

This land enters tapped.
{T}: Add {W} or {U}.

This land enters tapped.
{T}: Add {G} or {W}.

This land enters tapped.
{T}: Add {U} or {B}.

This land enters tapped.
{T}: Add {R} or {G}.

This land enters tapped.
{T}: Add {B} or {R}.

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.