Dungeons & Dragons: Chronicles of Mystara

Easiest to do in Shadow Over Mystara.

Select the Elf, she has the spell Polymorph Others. Hit , then to cycle your inventory until you find it.

Simply hit enemies with this spell and you will eventually have the achievement. There are also Scrolls and Rings of Polymorph Others as well, but they tend to be pretty rare. As you play the game with the Elf and level her up she will gain more casts for the spell, once you run out of casts simply die and the spell will be restocked.

Tier 3 is 25 enemies turned.

The spell itself is very short range, you must be standing right in front of the enemy for it to work. It only works on a handful of enemies. Gnolls are the easiest and most common enemies this will work on, I believe it works on Troglodytes as well, it also works on Dark Elves. It does not work on the tiny enemies (goblins, cobolds) or undead enemies (skeletons and Ghouls)

This one is pretty simple. You need the elf who has polymorph other. Cast it on weaker enemies and they will turn into cute little animals. heh. Wanna get it quick. Load a new game in arcade. Cast all your uses of the spell and either quit and restart or let them defeat you and reload with your spells refreshed.