Old One Eye

Trample
Other creatures you control have trample.
When Old One Eye enters, create a 5/5 green Tyranid creature token.
Fast Healing — At the beginning of your first main phase, you may discard two cards. If you do, return Old One Eye from your graveyard to your hand.

Old Rutstein

When Old Rutstein enters and at the beginning of your upkeep, mill a card. If a land card is milled this way, create a Treasure token. If a creature card is milled this way, create a 1/1 green Insect creature token. If a noncreature, nonland card is milled this way, create a Blood token.

Old Man of the Sea

You may choose not to untap Old Man of the Sea during your untap step.
{T}: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.

Nikya of the Old Ways

You can't cast noncreature spells.
Whenever you tap a land for mana, add one mana of any type that land produced.

Old-Growth Dryads

When Old-Growth Dryads enters, each opponent may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.

Old Ghastbark

Old-Growth Troll

Trample
When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has '{T}: Add {G}{G}' and '{1}, {T}, Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

Binding the Old Gods

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target nonland permanent an opponent controls.
II — Search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
III — Creatures you control gain deathtouch until end of turn.

Kami of Old Stone

Disciple of the Old Ways

{R}: Disciple of the Old Ways gains first strike until end of turn.

Old Stickfingers

When you cast this spell, reveal cards from the top of your library until you reveal X creature cards. Put all creature cards revealed this way into your graveyard, then put the rest on the bottom of your library in a random order.
Old Stickfingers's power and toughness are each equal to the number of creature cards in your graveyard.

Old Gnawbone

Flying
Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

Might of the Old Ways

Target creature gets +2/+2 until end of turn.
Coven — Then if you control three or more creatures with different powers, draw a card.

Dosan's Oldest Chant

Might of Old Krosa

Target creature gets +2/+2 until end of turn. If you cast this spell during your main phase, that creature gets +4/+4 until end of turn instead.