Fearless Fledgling

Landfall — Whenever a land you control enters, put a +1/+1 counter on Fearless Fledgling. It gains flying until end of turn.

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on Sprite Dragon.

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Tin Street Dodger

Haste
{R}: Tin Street Dodger can't be blocked this turn except by creatures with defender.

Lorehold Apprentice

Magecraft — Whenever you cast or copy an instant or sorcery spell, until end of turn, Spirit creatures you control gain "{T}: This creature deals 1 damage to each opponent."

Kor Blademaster

Double strike
Equipped Warriors you control have double strike.

Stormchaser Drake

Flying
Whenever Stormchaser Drake becomes the target of a spell you control, draw a card.

Sunblade Angel

Flying, first strike, vigilance, lifelink

Sharktocrab

{2}{G}{U}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on Sharktocrab, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Gitaxian Spellstalker

Trample, ward {2}, prowess, prowess (Each instance of prowess triggers separately.)

Khenra Spellspear

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{3}{U/P}: Transform Khenra Spellspear. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Khenra Spellspear // Gitaxian Spellstalker

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, Chandra's Spitfire gets +3/+0 until end of turn.

Prosperous Thief

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever one or more Ninja or Rogue creatures you control deal combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")