Cloudreach Cavalry

As long as you control a Bird, this creature gets +2/+2 and has flying.

Arcanist's Owl

Flying
When this creature enters, look at the top four cards of your library. You may reveal an artifact or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Cloudcrest Lake

{T}: Add {C}.
{T}: Add {W} or {U}. This land doesn't untap during your next untap step.

Cloudchaser Eagle

Flying
When this creature enters, destroy target enchantment.

Oltec Cloud Guard

Flying
When this creature enters, create a 1/1 colorless Gnome artifact creature token.

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Esper Cormorants

Skycloud Expanse

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.