Doran, Besieged by Time

Each creature spell you cast with toughness greater than its power costs {1} less to cast.
Whenever a creature you control attacks or blocks, it gets +X/+X until end of turn, where X is the difference between its power and toughness.

Trostani, Selesnya's Voice

Whenever another creature you control enters, you gain life equal to that creature's toughness.
{1}{G}{W}, {T}: Populate. (Create a token that's a copy of a creature token you control.)

Betor, Kin to All

Flying
At the beginning of your end step, if creatures you control have total toughness 10 or greater, draw a card. Then if creatures you control have total toughness 20 or greater, untap each creature you control. Then if creatures you control have total toughness 40 or greater, each opponent loses half their life, rounded up.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

Wall of Blossoms

Defender
When this creature enters, draw a card.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

Faeburrow Elder

Vigilance
This creature gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Felothar the Steadfast

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Tree of Redemption

Defender
{T}: Exchange your life total with this creature's toughness.

Fecund Greenshell

Reach
As long as you control ten or more lands, creatures you control get +2/+2.
Whenever this creature or another creature you control with toughness greater than its power enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. Otherwise, put it into your hand.

Baldin, Century Herdmaster

During your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Bark of Doran

Equipped creature gets +0/+1.
As long as equipped creature's toughness is greater than its power, it assigns combat damage equal to its toughness rather than its power.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Jaws of Defeat

Whenever a creature you control enters, target opponent loses life equal to the difference between that creature's power and its toughness.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Ancient Lumberknot

Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

Bedrock Tortoise

During your turn, creatures you control have hexproof.
Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

Sol Ring

Ancient Adamantoise

Vigilance, ward {3}
Damage isn't removed from this creature during cleanup steps.
All damage that would be dealt to you and other permanents you control is dealt to this creature instead.
When this creature dies, exile it and create ten tapped Treasure tokens.

Fangorn, Tree Shepherd

Treefolk you control have vigilance.
Whenever one or more Treefolk you control attack, add twice that much {G}.
You don't lose unspent green mana as steps and phases end.

Colfenor, the Last Yew

Vigilance, reach
Whenever Colfenor or another creature you control dies, return up to one other target creature card with lesser toughness from your graveyard to your hand.