This mod adds a few new potions that will either grow or shrink you depending on which you take. The growth potion makes you larger while increasing your attack and knockback resistance. But it will slow you down a bit.
Growth II will make you larger than that and increase your stats even more.
You’ll be a god against any mobs for at least a few minutes!
Shrinking, on the other hand, makes you smaller, faster, and you can jump significantly higher but your damage and knockback resistance goes down a bit.
And Shrinking II makes you even smaller and gives you the handy ability to climb anything!