Flying, lifelink
When Deep-Cavern Bat enters, look at target opponent’s hand. You may exile a nonland card from it until Deep-Cavern Bat leaves the battlefield.
The first shriek locates the prey. The second immobilizes it.
If Deep-Cavern Bat leaves the battlefield before its last ability resolves, you'll still look at the target opponent's hand, but you won't exile any cards from it.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.