This could be a 0 cost card.
If it’s gonna be shot by a fireball, that’s amazing value on it’s own and worth 4 mana even if it didn’t do anything else. But it does, it’s a beast with charge, that’s huge.
Think of it like a boar: 1/1 Charge, then with 2 extra mana you add 1/3 stats. That’s a fair card. But it’s a Legendary, so you have a narrow but powerful synergy, that’s the effect. The extra stat? That’s just too much. It can’t be dealt with by frostbolt and ping, that’s just evil and if mage goes second that’s even worse.
So, to make it a really powerful tech in any hunter deck, make it 2-4. It’s still OP, but it’s a legendary, so you’ll only have one.