Dross Scorpion

Whenever Dross Scorpion or another artifact creature dies, you may untap target artifact.

Thornbite Staff

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."
Whenever a Shaman creature enters, you may attach Thornbite Staff to it.
Equip {4}

Jan Jansen, Chaos Crafter

Haste
{T}, Sacrifice an artifact creature: Create two Treasure tokens.
{T}, Sacrifice a noncreature artifact: Create two 1/1 colorless Construct artifact creature tokens.

Mobile Garrison

Whenever Mobile Garrison attacks, untap another target artifact or creature you control.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Thistledown Players

Whenever Thistledown Players attacks, untap target nonland permanent.

Puppet Strings

{2}, {T}: You may tap or untap target creature.

Acrobatic Leap

Target creature gets +1/+3 and gains flying until end of turn. Untap it.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Tenth District Veteran

Vigilance
Whenever Tenth District Veteran attacks, untap another target creature you control.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Jandor's Saddlebags

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.