CardName: Sulphurslick Pools
Cost:
Type: Land
Pow/Tgh: /
Rules Text: Sulphurslick Pools enters the battlefield tapped.
{T}: Add {R} or {U} to your mana pool.
{4}{R}{U}: Sulphurslick Pools becomes a copy of target
creature until end of turn. It's still a land.
Flavour Text:
Set/Rarity: Multiverse Design Challenge None
Sulphurslick Pools
Land
Sulphurslick Pools enters the battlefield tapped.
: Add or to your mana pool.
: Sulphurslick Pools becomes a copy of target creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.
See Challenge # 137. A simpler version of link's Mirrormere.
Very nice. Probably makes a bit more sense in these colors, at least without the size-changing.