Own Some

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Have

Alania, Divergent Storm

Whenever you cast a spell, if it's the first instant spell, the first sorcery spell, or the first Otter spell other than Alania you've cast this turn, you may have target opponent draw a card. If you do, copy that spell. You may choose new targets for the copy.

Coruscation Mage

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Island

Hidden Grotto

When Hidden Grotto 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.

Eddymurk Crab

Flash
This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Eddymurk Crab enters tapped if it's not your turn.
When Eddymurk Crab enters, tap up to two target creatures.

Tempest Angler

Whenever you cast a noncreature spell, put a +1/+1 counter on Tempest Angler.

Valley Floodcaller

Flash
You may cast noncreature spells as though they had flash.
Whenever you cast a noncreature spell, Birds, Frogs, Otters, and Rats you control get +1/+1 until end of turn. Untap them.

Pearl of Wisdom

This spell costs {1} less to cast if you control an Otter.
Draw two cards.

War Squeak

Enchant creature
When War Squeak enters, target creature an opponent controls can't block this turn.
Enchanted creature gets +1/+1 and has haste.

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Kindlespark Duo

{T}: Kindlespark Duo deals 1 damage to target opponent.
Whenever you cast a noncreature spell, untap Kindlespark Duo.