Exotic Far Harad Butterflies
Butterflies are harmless mobs that can be seen in many biomes in Middle Earth. They come in many different colors such as red, white, orange, yellow, and purple. In Mirkwood, the purple butterflies emit a purple trail of glowing particles. Among the Mallorn trees in Lothlórien you can see white butterflies that emit a blue trail of glowing particles. In Far Harad, an abundance of flamboyantly coloured butterflies can be found. If you kill a butterfly, you get the achievement "Merciless" and earn the respective title.
Since Beta 22 you can catch a butterfly to jar, by hanging empty Butterfly Jar in hand and clicking with it on a butterfly. It will give you an achievement "Fluttering By".
Note: The butterflies will always be turned at player's side, just like fire in furnances.
Three different butterflies locked in jars.