msem-instigator

Flying
Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Tireless Vulture enters, if tribute wasn't paid, each opponent loses 3 life. You gain life equal to the life lost this way.

Flying
Tizerus Bats can't block unless you control another creature with flying.

Creatures with power 4 or greater can't attack or block unless their controller pays {2} for each of those creatures.

Whenever a creature you control attacks, you may sacrifice a Treasure. If you do, that creature can't be blocked this turn.

When Tomb-Raider Duo enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Haste
Whenever Tortle Waymaker becomes blocked, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Trample

Reach
Towering Silkweaver can block an additional creature each combat.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Tracker of Wild Places envisions a creature card, you may untap a permanent you control.

Flash
When Trade Route Bandit enters, you may have each player draw two cards.

Rapport — Whenever Trae, Serpent's Grasp and at least one other creature you control become tapped, each player draws a card. Then Trae, Serpent's Grasp deals 2 damage to each opponent with four or more cards in hand.

First strike
Angel spells you cast cost {2} less to cast.
As long as you control an Angel, prevent all noncombat damage that would be dealt to Traft, Lunarch's Edge.

When Transcended Explorer enters, if you control another enchantment, draw a card.

Wanderlust — When Transnaturalist enters, if you control four or more differently named lands, you may return target creature to its owner's hand.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
{1}{W}, Sacrifice a creature or enchantment: Scry 1, then draw a card. Activate only if Trauma Surgeon has a +1/+1 counter on it.

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
When Treacherous Devil enters, if an opponent passed the trial, that player gains control of Treacherous Devil.

When Treacherous Warden enters, search your library for a card, put into your graveyard, then shuffle.
Whenever a creature enters from your graveyard, each opponent loses 2 life and you gain 2 life.

Whenever another nontoken creature you control enters, that creature gains haste until end of turn. Then Tremor Seer deals 1 damage to any target.

When Trepid Deserters enters, target creature you control gets +2/+0 until end of turn.

Goblincycling {1}{R}, Warriorcycling {1}{R} ({1}{R}, Discard this card: Search your library for a Goblin or Warrior card, reveal it, and put it into your hand. Then shuffle.)

Trample
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Tribal Guard mentors a creature, that creature gains trample until end of turn.

{G}, {T}: Target creature with power 4 or greater fights any number of target creatures you control.

Triumvirate Infiltrator has flying as long as you control another Elemental.

Rhapsody {4}{W}{W} (Pay {4}{W}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Triumvirate Strategist has first strike as long as it's attacking.

At the beginning of your upkeep, if you control a legendary creature, put a +1/+1 counter on Trossingen Warden.