Gerrard's Command

Untap target creature. It gets +3/+3 until end of turn.

Ghostly Touch

Enchant creature
Enchanted creature has "Whenever this creature attacks, you may tap or untap target permanent."

Chakram Retriever

Partner with Chakram Slinger (When this creature enters, target player may put Chakram Slinger into their hand from their library, then shuffle.)
Whenever you cast a spell during your turn, untap target creature.

Captain of the Mists

Whenever another Human you control enters, untap this creature.
{1}{U}, {T}: You may tap or untap target permanent.

Dauntless Aven

Flying
Whenever this creature attacks, untap target creature you control.

Emerald Charm

Choose one —
• Untap target permanent.
• Destroy target non-Aura enchantment.
• Target creature loses flying until end of turn.

Hidden Strings

You may tap or untap target permanent, then you may tap or untap another target permanent.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Gift of Growth

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Untap target creature. It gets +2/+2 until end of turn. If this spell was kicked, that creature gets +4/+4 until end of turn instead.

Disciple of the Ring

{1}, Exile an instant or sorcery card from your graveyard: Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• This creature gets +1/+1 until end of turn.
• Tap target creature.
• Untap target creature.

Fyndhorn Brownie

Jandor's Saddlebags

Clever Conjurer

Mage Hand — {T}: Untap target permanent not named Clever Conjurer. Activate only as a sorcery.

Beacon Hawk

Flying
Whenever this creature deals combat damage to a player, you may untap target creature.
{W}: This creature gets +0/+1 until end of turn.

Derevi, Empyrial Tactician

Flying
When Derevi enters and whenever a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.

Dream's Grip

Choose one —
• Tap target permanent.
• Untap target permanent.
Entwine {1} (Choose both if you pay the entwine cost.)

Inspirit

Untap target creature. It gets +2/+4 until end of turn.

Infuse

Untap target artifact, creature, or land.
Draw a card at the beginning of the next turn's upkeep.

Djeru's Resolve

Untap target creature. Prevent all damage that would be dealt to it this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Aphetto Alchemist

{T}: Untap target artifact or creature.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Cat-Owl

Flying
Whenever this creature attacks, untap target artifact or creature.

Curse of Inertia

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may tap or untap target permanent of their choice.

Civic Gardener

Whenever this creature attacks, untap target creature or land.

Initiate's Companion

Whenever this creature deals combat damage to a player, untap target creature or land.