mtg.wtf

Fear
{B}: Undercity Shade gets +1/+1 until end of turn.

Renown 1
{2}{G}: Regenerate Undercity Troll.

Whenever Undercover Butler attacks the player with the most life or tied for most life, it can't be blocked this turn.

Whenever Undercover Crocodelf deals combat damage to a player, investigate.
Disguise {3}{G/U}{G/U}

You may have Undercover Operative enter as a copy of any creature on the battlefield, except it enters with a shield counter on it if you control that creature.

Deathtouch

Underdark Beholder enters the battlefield with ten eyestalk counters on it.
If Underdark Beholder would be dealt damage, remove that many eyestalk counters from it instead. If you can't, sacrifice it.
Whenever Underdark Beholder attacks, reveal cards from the top of your library until you reveal an instant, sorcery, or enchantment card with converted mana cost less than the number of eyestalk counters on Underdark Beholder. You may cast it without paying its mana cost. Shuffle your library.

Menace
When Underdark Explorer enters, you take the initiative.

{T}: Add {C}.
{5}, {T}, Exile Underdark Rift: Roll a d10. Put target artifact, creature, or planeswalker into its owner's library just beneath the top X cards of that library, where X is the result. Activate only as a sorcery.

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to pay Un-costs.

Underground Mortuary enters tapped.
When Underground Mortuary enters, surveil 1.

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

If damage would be dealt to Undergrowth Champion while it has a +1/+1 counter on it, prevent that damage and remove a +1/+1 counter from Undergrowth Champion.
Landfall — Whenever a land you control enters, put a +1/+1 counter on Undergrowth Champion.

At the beginning of your upkeep, return target land card from your graveyard to the battlefield tapped.

Undergrowth Scavenger enters with a number of +1/+1 counters on it equal to the number of creature cards in all graveyards.

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Whenever an artifact you control enters, you may pay {1}. If you do, each opponent loses 1 life and you gain 1 life.
{1}{B}, Sacrifice Underhanded Designs: Destroy target creature. Activate only if you control two or more artifacts.

Vigilance
When Undermountain Adventurer enters, you take the initiative.
{T}: Add {G}{G}. If you've completed a dungeon, add six {G} instead.

If you would draw a card, instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard.
Pay 4 life: Underrealm Lich gains indestructible until end of turn. Tap it.

Flash
Undersea Invader enters tapped.

{B}, {T}, Discard a card: Return target creature card from your graveyard to your hand.

Creatures with islandwalk can be blocked as though they didn't have islandwalk.

When you unlock this door, surveil 2.

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard.
At the beginning of the end step, sacrifice Underworld Breach.