Healthy

Potion effect that subtly gives you health at a random interval.
Instead of healing you, it directly adds to your health.

The effect is reversed on undead mobs. (Hurt instead of heal)

The formula:
The amount you get healed is based on the level of the potion. (1 health for level I, 2 for level II...)
At level I, 1/60 chance to be healead every tick. On average, you are healed once every 3 seconds.
At level II, 1/50 chance every tick.
At III, 1/40 chance. You get healed on average once per 2 seconds.
At IV, 1/30 chance.
At V, 1/20 chance. On average, healed once per second. The sound effect stops playing at this point.
At VI, 1/10 chance. Healed 2 times per second on average.
At VII and above, you're healed every tick.