"Flee all you like. The further you run the more firmly I feel your heartbeat."

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on this creature.
When this creature leaves the battlefield, draw a card for each +1/+1 counter on it.

The Lost Caverns of Ixalan Commander

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Jumpstart 2022

Crimson Vow Commander

Commander 2021

Treasure Chest

If enough -1/-1 counters are put on Bloodtracker at the same time to make its toughness 0 or less, the number of +1/+1 counters on it before it got any -1/-1 counters will be used to determine how many cards you draw. For example, if there are three +1/+1 counters on Bloodtracker and it gets six -1/-1 counters, you'll draw three cards. That's because Bloodtracker's triggered ability checks the creature's existence just before it leaves the battlefield, and it still has all those counters on it at that point.