Sniper

Sniper enters the battlefield face down: while it's
face down, it has hexproof and can't attack.
When Sniper enters the battlefield, you may
search your library for a card named Spotter and
put it into your hand. Then shuffle your library.
Headshot —{r}, {t}: Turn face up: destroy target
tapped creature.
{c}{c}, {t}: Turn face down.
"Invisibility is their skill. But killing from a mile
away... that's a gift."