Emperor Crocodile

When you control no other creatures, sacrifice Emperor Crocodile.

Lurking Crocodile

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Undercity Necrolisk

{1}, Sacrifice another creature: Put a +1/+1 counter on Undercity Necrolisk. It gains menace until end of turn. Activate only as a sorcery. (It can't be blocked except by two or more creatures.)

Guul Draz Mucklord

When Guul Draz Mucklord dies, put a +1/+1 counter on target creature you control.

Nema Siltlurker

Plated Rootwalla

{2}{G}: Plated Rootwalla gets +3/+3 until end of turn. Activate only once each turn.

Crocanura

Reach (This creature can block creatures with flying.)
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Wardscale Crocodile

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Tenacious Hunter

As long as a creature has a -1/-1 counter on it, Tenacious Hunter has vigilance and deathtouch.

Rootwalla

{1}{G}: Rootwalla gets +2/+2 until end of turn. Activate only once each turn.

Baleful Ammit

Lifelink
When Baleful Ammit enters, put a -1/-1 counter on target creature you control.

Dross Crocodile

Golgari Brownscale

When Golgari Brownscale is put into your hand from your graveyard, you gain 2 life.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Skeletal Crocodile

Catacomb Crocodile

Chevill, Bane of Monsters

Deathtouch
At the beginning of your upkeep, if your opponents control no permanents with bounty counters on them, put a bounty counter on target creature or planeswalker an opponent controls.
Whenever a permanent an opponent controls with a bounty counter on it dies, you gain 3 life and draw a card.

Hagra Crocodile

Hagra Crocodile can't block.
Landfall — Whenever a land you control enters, Hagra Crocodile gets +2/+2 until end of turn.

Kheru Dreadmaw

Defender
{1}{G}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness.

Ammit Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Whenever an opponent casts a spell, put a -1/-1 counter on Ammit Eternal.
Whenever Ammit Eternal deals combat damage to a player, remove all -1/-1 counters from it.

Bloodspore Thrinax

Devour 1 (As this enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)
Each other creature you control enters with an additional X +1/+1 counters on it, where X is the number of +1/+1 counters on Bloodspore Thrinax.

Vivien's Crocodile

Vivien's Crocodile gets +1/+1 as long as you control a Vivien planeswalker.

Rootwater Alligator

Sacrifice a Forest: Regenerate Rootwater Alligator.

Deathgazer

Whenever Deathgazer blocks or becomes blocked by a nonblack creature, destroy that creature at end of combat.

Algae Gharial

Shroud (This creature can't be the target of spells or abilities.)
Whenever another creature dies, you may put a +1/+1 counter on Algae Gharial.

Crocodile of the Crossing

Haste
When Crocodile of the Crossing enters, put a -1/-1 counter on target creature you control.

Scaled Behemoth

Aetherwind Basker

Trample
Whenever Aetherwind Basker enters or attacks, you get {E} (an energy counter) for each creature you control.
Pay {E}: Aetherwind Basker gets +1/+1 until end of turn.

Whiptongue Hydra

Reach
When Whiptongue Hydra enters, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.

Shefet Monitor

Cycling {3}{G} ({3}{G}, Discard this card: Draw a card.)
When you cycle Shefet Monitor, you may search your library for a basic land card or a Desert card, put it onto the battlefield, then shuffle. (Do this before you draw.)

Flycatcher Giraffid

Flycatcher Giraffid enters with your choice of a vigilance counter or a reach counter on it.

Stonefare Crocodile

{2}{B}: Stonefare Crocodile gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Brooding Saurian

At the beginning of each end step, each player gains control of all nontoken permanents they own.

Dukhara Scavenger

When Dukhara Scavenger enters, you may put target artifact or creature card from your graveyard on top of your library.