Whenever another Zombie enters the battlefield under your control, you may tap target artifact or creature.

: Untap target land.

Creatures you control with flying get +1/+1.

Flying (This creature can't be blocked except by creatures with flying or reach.)
: Furnace Whelp gets +1/+0 until end of turn.

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, and put those cards onto the battlefield tapped. Then shuffle your library.

Cats you control have protection from Rats. (They can't be blocked, targeted, or dealt damage by Rats.)
At the beginning of your end step, target opponent creates a 1/1 black Rat creature token with deathtouch.
Whenever a Rat dies, put a +1/+1 counter on each Cat you control.

Flash
Flying
Cycling (, Discard this card: Draw a card.)
When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

Deathtouch
When Ruin Rat dies, exile target card from an opponent's graveyard.

Scrounging Bandar enters the battlefield with two +1/+1 counters on it.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Scrounging Bandar onto another target creature.

When Tishana's Wayfinder enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

: Put X +1/+1 counters on target land you control. That land becomes a 0/0 Elemental creature with haste. It's still a land.

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)
Flying