Meekstone

Creatures with power 3 or greater don't untap during their controllers' untap steps.

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Arcades Sabboth

Flying
At the beginning of your upkeep, sacrifice Arcades Sabboth unless you pay {G}{W}{U}.
Each untapped creature you control gets +0/+2 as long as it's not attacking.
{W}: Arcades Sabboth gets +0/+1 until end of turn.

Fountain of Youth

Savannah

Birds of Paradise

Transmute Artifact

Sacrifice an artifact. If you do, search your library for an artifact card. If that card's mana value is less than or equal to the sacrificed artifact's mana value, put it onto the battlefield. If it's greater, you may pay {X}, where X is the difference. If you do, put it onto the battlefield. If you don't, put it into its owner's graveyard. Then shuffle.

City of Brass

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

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Dragon Engine

{2}: Dragon Engine gets +1/+0 until end of turn.

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Icy Manipulator

{1}, {T}: Tap target artifact, creature, or land.

Tropical Island

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.