Trample
Whenever Skophos Raid-Veteran deals combat damage to a player or planeswalker or becomes the target of a spell you control, create a tapped Treasure token.

Flying
When Skylance Escort enters, put a vigilance counter on each creature you control.

Sleeper Insurgent doesn't untap during your untap step.
Whenever Sleeper Insurgent becomes the target of a spell or ability you control, untap it. This ability triggers only once each turn.

Flash
Flying
When Sleeper Strix enters, tap up to one target creature.
You may look at an additional card each time you surveil.

When Smiling Sludge enters, create a Berry token.
Whenever you sacrifice a nonland permanent, target opponent loses 1 life and you gain 1 life.

Equipped creature gets +1/+1.
As long as equipped creature was activated this turn, it gets an additional +2/+2 and can attack as though it were untapped.
Equip {2}

Return target creature to its owner's hand. If you controlled it, create a token that's a copy of it. Otherwise, create a 0/0 colorless Robot artifact creature token with a +1/+1 counter on it.

When Sola enters, create a Treasure token.
{2}, Sacrifice a Treasure: You gain 3 life.
{2}, Sacrifice a Treasure: Draw a card.

When Soothing Singer enters, exile target nonland permanent you don't control until Soothing Singer leaves the battlefield.
{1}{W}: Soothing Singer gets +0/+2 until end of turn.

Flying
When Soul's Sunset enters, exile up to two target cards from graveyards. You gain 2 life.
Surface {4}{B}{B}

Return up to three target cards from your graveyard to your hand. Exile Soulless Archive.

Prevent all damage that would be dealt to Soundproof Transport by creatures blocking it.

At the beginning of your end step, if you control three or more untapped lands, up to one target nonland permanent doesn't untap during its controller's next untap step.

Counter target activated or triggered ability from a nonland source. If a creature's ability is countered this way, you may pay {1}{C}. If you do, exile that creature.

{T}: Add one mana of any color.
At the beginning of combat on your turn, if you've spent at least five mana to cast spells this turn, untap Speaker of Endless Winter and put a +1/+1 counter on it.

Whenever a Ruin you control becomes spellcharged, put a +1/+1 counter on Speaker of the Forebears.
Sacrifice Speaker of the Forebears: Add an amount of {R} equal to the number of +1/+1 counters on it.

Whenever another creature you control enters, you may pay {X}{X}. If you do, put X +1/+1 counters on that creature.
{T}: Add one mana of any color.

Landfall — Whenever a land you control enters, put a +1/+1 counter on Spore Collector. It gains your choice of vigilance, first strike, or lifelink until end of turn.

Create a 1/1 green Saproling creature token for each permanent card you own in your graveyard and in exile.
Flashback {2}{G}{G}

As an additional cost to cast this spell, exile any number of permanent cards from your graveyard. This spell costs {1} less to cast for each card exiled this way.
Deathtouch
When Sporeback Jargah dies, return a card exiled with it of an opponent's choice to its owner's hand.

Flying
Drop — When Staggering Wyvern enters, if you didn't cast any creature spells during your last turn, tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Whenever you cast an instant, sorcery, or Aura spell that targets only Star-Seeking Dreamer, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

First strike
Landfall — Whenever a land you control enters, you may tap target creature.

Exile the top two cards of target opponent's library. You may play them until the end of your next turn, and mana of any type can be spent to cast them.

Any number of creatures you control fight different creatures you don't control. Each other creature you control gets +3/+3 and gains trample until end of turn.