msem-instigator

As an additional cost to cast this spell, exile a creature card from your graveyard.
Create a tapped 2/3 black Mummy creature token.

When Njel Crocodile enters the battlefield, you may have it fight target creature. (Each deals damage equal to its power to the other.)

Search your library for a land card and put that card onto the battlefield tapped with a venom counter on it. It gains “Whenever this land is tapped for mana, you lose 1 life.” Then shuffle.

{2}, Remove a counter from another permanent you control: Ruthless Monstrosity gets +2/+2 until end of turn.

Pay any amount of life. Look at twice that many cards from the top of your library and put one into your hand. Exile the rest.

Target creature gets -3/-3 until end of turn. If that creature would die this turn, exile it instead.

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Choose target opponent. Scry 3, then reveal the top card of your library. The chosen player discards an amount of cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

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

Menace (This creature can't be blocked except by two or more creatures.)
Avatar of Basat can't block.

Choose one —
• Target creature gets +2/-1 until end of turn.
• Basat Charm deals 3 damage to target player or planeswalker.

Menace
Cat creatures you control have menace.
When Basat Priest enters the battlefield, create a 2/2 white Cat creature token.

Target creature gets +3/+3 until end of turn.

Haste
When Caravan Engulfer enters the battlefield, creatures you don't control can't block this turn.

Exile target card from your graveyard. You may play it this turn.

Create two 1/1 red and white Sand Warrior creature tokens.

Desert Wurms can't be blocked by creatures with flying.
When Desert Wurms enters the battlefield, create two 6/6 red Wurm creature tokens with “This creature can't be blocked by creatures with flying.”
When Desert Wurms is put into a graveyard from anywhere, shuffle it into its owner's library.

Enchant creature
Enchanted creature gets +2/+2 and can't be blocked as long as defending player controls a Desert.

Reach (This creature can block creatures with flying.)

Haste
Menace (This creature can't be blocked except by two or more creatures.)
{4}{R}{R}: Ferocious Desert-Hunter gets +X/+0 until end of turn, where X is its power.

Fire from Above deals 2 damage to target opponent and each creature with flying that player controls.

Whenever you cast a spell during an opponent's turn, Haughty Priest deals 1 damage to that player.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Whenever a creature blocks, Heat of Battle deals 1 damage to that creature's controller.

Enchant creature
Enchanted creature gets +2/+0 and has first strike.
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)