Hexgold Slith [Modern Horizons 3]

When Hexgold Slith enters the battlefield, you get EE (two energy counters).

Whenever Hexgold Slith attacks, you may pay EE. If you do, it gains first strike
until end of turn.

Whenever Hexgold Slith deals combat damage to a player, put a +1/+1 counter on it.