Mallorn Ent

The Mallorn Ent is an Ent boss added in beta 24 for evil aligned players to fight. It is a boss version of the normal Ent. The Mallorn Ent can spawn with different names, suggesting that it is a dominant ent rather than one character. It glows and does not attack people with positive fangorn alignment.

Defeating the Mallorn Ent will earn you the achievement "Wrath of the Forest" It will also give you the title "Entslayer" and give you the "Entslayer's Shield"

Summoning
To summon it in survival mode, you need to place a normal Mallorn Sapling on a dirt, grass or podzol block and right-click it with a Gulduril Crystal, creating a Corrupt Mallorn Sapling. This sapling has to be placed in the Fangorn Forest, then some Ents will appear next to it and try to cure the corrupted sapling, three Ents have to be killed to spawn the Mallorn Ent (with only one sapling).

It can also be summoned using /lotr_summon lotr.MallornEnt

Once you summon it, a health bar similar to the enderdragon's appears at the top of the screen.

Combat
It can summon ents and huorns, also can send a whirlwind of leaves at you. It can jump considerably high, and heal by "absorbing" the essence of trees.

After emptying its health bar for the first time it will say a phrase saying something like:

"O Kementari, hear me! Strengthen me against the iron-bite of this little orc!"

(Kementari is a name for Yavanna, the creator of the ents, her more common name may also be used)

It will then commence to glow green and gain what seems to be infinite health.

However, to kill it, you'll need fire (lava or through a flint and steel) to damage it significantly. An axe can do less damage, but is more effective than a sword. About halfway through the second health bar, the boss weakens and hits become increasingly effective.Upon death it drops around half a stack each of Mallorn sticks and Mallorn logs, a Charred Mallorn Mace, and a Mallorn Ent Trunk as a trophy.