Fluttershy

Defender, flying
{1}, {T}: Put a +1/+1 counter on each creature with a tail target player controls. Stare down up to one target creature until end of turn. (It can't attack or block as long as you're looking directly at it.)

Rainbow Dash

Flying, haste
Whenever a creature you control with flying and/or haste attacks, you get 20% cooler. (You start at 0% coolness.)
Sonic Rainboom — {T}: If you're at least 100% cool, add {W}{U}{B}{R}{G}, draw a card, and reset your coolness.