Have

Cactarantula

This spell costs {1} less to cast if you control a Desert.
Reach
Whenever this creature becomes the target of a spell or ability an opponent controls, you may draw a card.

Spinewoods Armadillo

Reach
Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
{1}{G}, Discard this card: Search your library for a basic land card or a Desert card, reveal it, put it into your hand, then shuffle. You gain 3 life.

Sandstorm Verge

{T}: Add {C}.
{3}, {T}: Target creature can't block this turn. Activate only as a sorcery.

Ankle Biter

Blacksnag Buzzard

Flying
This creature enters with a +1/+1 counter on it if a creature died this turn.
Plot {1}{B} (You may pay {1}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Festering Gulch

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {B} or {G}.

Hardbristle Bandit

{T}: Add one mana of any color.
Whenever you commit a crime, untap this creature. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Voracious Varmint

Vigilance
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Mirage Mesa

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Mourner's Surprise

Return up to one target creature card from your graveyard to your hand. Create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Colossal Rattlewurm

Colossal Rattlewurm has flash as long as you control a Desert.
Trample
{1}{G}, Exile this card from your graveyard: Search your library for a Desert card, put it onto the battlefield tapped, then shuffle.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.

Desperate Bloodseeker

Lifelink
When this creature enters, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Dance of the Tumbleweeds

Spree (Choose one or more additional costs.)
+ {1} — Search your library for a basic land card or a Desert card, put it onto the battlefield, then shuffle.
+ {3} — Create an X/X green Elemental creature token, where X is the number of lands you control.

Swamp

Desert's Due

Target creature gets -2/-2 until end of turn. It gets an additional -1/-1 until end of turn for each Desert you control.

Conduit Pylons

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Patient Naturalist

When this creature enters, mill three cards. Put a land card from among the milled cards into your hand. If you can't, create a Treasure token. (To mill three cards, put the top three cards of your library into your graveyard.)

Badlands Revival

Return up to one target creature card from your graveyard to the battlefield. Return up to one target permanent card from your graveyard to your hand.