Check out my new Flower Pot Resource Pack for Java Edition
When a Monster type mob spawns it will calacute its Y level and scale its damage accordingly. using the math fomula "depthMultiplier = 1.0 + ((64 - y) / 10) * 0.1", Every -10 Y levels increases multiplier by 0.1x. this can be disabled with the gamerule "hostileCaveBuff" being set to false.