Multiattack

The altar flame golem makes two slam attacks.

Slam

Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage plus 11 (2d10) fire damage.

Flame Breath (Recharge 5-6)

The golem breathes fire in a 30-foot cone. Each creature in that area must make a DC 16 Dexterity saving throw, taking 36 (8d8) fire damage on a failed save, or half as much damage on a successful one.