Whenever Radagast or another nontoken creature you control enters, look at the top X cards of your library, where X is that creature's mana value. You may reveal a creature card that doesn't share a creature type with a creature you control from among those cards and put it into your hand. Put the rest on the bottom of your library in a random order.

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Permanents you control gain hexproof and indestructible until end of turn.

Flying
Whenever you discard a nonland card, put a +1/+1 counter on target Goblin you control.
Whenever you discard a land card, create a tapped Treasure token.

Whenever this creature or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Whenever Hammer of Nazahn or another Equipment you control enters, you may attach that Equipment to target creature you control.
Equipped creature gets +2/+0 and has indestructible.
Equip

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Other Rats you control have toxic 1.
When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Permanents you control gain hexproof and indestructible until end of turn.

Choose target creature you control. It deals damage equal to its power to each other creature. If this spell was cast from a graveyard, discard your hand and draw four cards.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Death Grasp deals X damage to any target. You gain X life.

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip

Each player shuffles their hand and graveyard into their library. You exile the top ten cards of your library. Then each player draws up to seven cards.

Activated abilities of creatures you control cost less to activate. This effect can't reduce the mana in that cost to less than one mana.

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

: Add .

Trample
When this creature dies, create a 6/6 black Wurm creature token with trample.

At the beginning of each opponent's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.

Whenever a player casts a red spell, you may pay . If you do, you gain 1 life.

Permanents you control gain hexproof and indestructible until end of turn.