Tiamat, the Dusk Queen

Whenever a creature dealt damage by Tiamat this
turn dies, put a +1/+1 counter on Tiamat.

As long as Tiamat has two or more +1/+1
counters on it, it has flying.

As long as Tiamat has three or more +1/+1
counters on it, it has lifelink.

As long as Tiamat has four or more +1/+1
counters on it, it has wither.