I copied this from the Paladin Forum. I know alot of people start to think to themselves, why am I doing this, all I do is level, fight the same mobs for month after month. I myself know what HMN's are and the only ones in knew by name were aqaurius, Behemoth, and serket, but I never realized how long and how many people some of these fights take, a 5 hour fight sounds fun, but there are some people that would never be able to make that, look at all the people that cant stay long enough to do a promyvion. Anyways, here is what I copied, a list of all HNM's and a little info on each of them. Enjoy!!
Training Stuff
These mobs are not considered true HNMs and most can be taken down by very few 75's, but they are a nice way to experience the thrill of the fight at lower levels. If you want to slowly wean yourself onto the idea of getting smashed for 3 digit damage regularly, try these in your 60's.
Roc
Recommended: 60+ with alliance, 70+ with party
This is arguably the easiest 'HNM' that people regularly hunt. He is really really easy and people in their 60's should have no problems taking him down.
King Arthro
Recommended: 60+ with alliance, 70+ with party
Affectionately known as KA, this NM is really easy. The only trouble is actually getting claim, because he drops the Speed Belt, a very highly-prized item. So expect to have plenty of competition at his spawn.
Lumber Jack
Recommended: 60-69 with alliance, 70+ with party
Another easy one for level 60's for those who wish to start early.
Aquarius
Recommended: 60-65 with alliance, 65-69 with party, 70+ with 2-3
The drop rate of Damascene Cloth (used to make Vermillion Cloaks) is totally horrible on this guy. He's a slightly greater challenge for 65's to 70's. As a crab he's pretty harmless in terms of 'devastating attacks'. In fact, a small alliance or full party of higher 60's can try him. Great way for plds to get used to getting hit hard.
Simurgh
Recommended: 65-70 with alliance, 70+ with party
Another bird-type mob, but a tiny step above Roc. He should pose no problem as well. 2 level 75's of the proper jobs can take him down comfortably, but for level 60's he is a pretty nice alliance challenge.
The Not-So-Training stuff
These ones are slightly tougher and will require a bit more effort (as well as higher level). Great introductory stuff for level 70's as well as weaning off the smaller stuff. These ones also drop bigger and better loot. Yay!
Adamantoise
Recommended: 65-70 with alliance, 70+ with party
This guy is so easy to experienced 75's that we call him the Skill-up Rock. The only problem are the links surrounding him, and the fact that you might end up with the +1 version of this guy (not introductory stuff!), Aspidochelone. Otherwise, this fellow is very very easy. Has close to no ouchy specials, and hits like a baby. Just sit on him and he'll cry inside that shell.
Behemoth
Recommended: 65-69 with alliance, 70+ with party
Contrary to popular belief, I find the regular Behemoth -easier- than say, Bune. He doesn't even hit as hard, and he has no Meteor like his big brother, King Behemoth. He's just a purple dude who looks scary, but can be eaten alive. Get in there and poke him.
Serket
Recommended: 65-72 with alliance, 73-75 with party
Popular target for training people and for established shells out for money. Serket has a few nasty attacks and will give you your introduction to the wonderful world of hate-reset attacks that stun and throw you from one end of the room to the other. Also he will give you your first taste of AOE attacks and for all your effort, he might drop a Venomous Claw (used for making Scorpion Harness).
Bune
Recommended: 65-72 with alliance, 73-75 with party
Remember when you were levelling in Gustav you happened across this guy? Yes, now's your turn to actually poke him. He has normal dragon attacks, breath, hurricane wing and such, and he hits pretty hard for a HNM his level. This is a good time to see if your white mages can do a nice job healing you sufficiently in preparation for tougher fights, and if you can keep the hate off them.
Lord of Onzozo / Charybdis
Recommended: 70+ with alliance
These guys are pretty similar, although I personally have somethng against Charybdis because he drops my sword <.<;; Basically, they don't hit for much, but they hit fast. Another test of your healers' curing skills.
Za'Dha Adamantking / Tzee Xicu the Manifest / Overlord Bakgodek
Recommended: 70+ with alliance
The 3 beastmen gods. They're pretty similar in terms of difficulty, but they each have different job classes and have their own beastmen-specific attacks (like orcs have that Slam Dunk thing). Comfortable for practising alliance fighting.
Capricious Cassie
Recommended: 70+ with party
She's a mean monster, but only because she has all these horrid attacks. Sweet Breath that fills you up with every status effect in the game, hate-rest Tentacle attack thingy, and many, many worse things. Eww. Simply eww. I hate going to fight her :/
No more training wheels!
Not so easy stuff now kiddos... some of these ones actually drop Abjuration! Omg! Yes, you can get Koenig now!
Fafnir
Recommended: 70+ with alliance
This guy is a pushover. Really. He just looks mean, but he isn't mean at all.
Nidhogg
Recommended: 70+ with alliance
Fafnir+1. It seems as if SE upgraded Nidhogg's difficulty in a recent patch, but otherwise he uses about the same things as Fafnir. He tends to hit a little harder I think.
Genbu
Recommended: 70+ with alliance
One of the directional gods in Tu'lia. Genbu is IMO the easiest of the four gods, because he attacks so slow (well, he is a tortoise). Think of him as the Adamantoise's bigger brother.
Suzaku
Recommended: 70+ with alliance
The bird god, and also a pushover once you get past his Chainspell 2hr. I won't say exactly how because different linkshells have different ways of fighting him, but aside from his 2hr the other attacks are nothing to worry about.
Aspidochelone
Recommended: 70+ with alliance
Adamntoise+1... he's ANOTHER tortoise. No comment.
Seiryu
Recommended: 70+ with alliance
Dragon god. He can be nasty, but well.. he's a dragon. Basic HNM tactics = teh win. Just go at him as you've done with the other HNMs and all will be well.
Byakko
Recommended: 70+ with alliance
I listed him last because some linkshells have trouble with him, although I personally find Seiryu more of a thorn than Byakko. This guy is difficult for a nin to tank because of his frequent Triple Attack, so plds, this is mostly your fight.
The big boys
Now we're rolling.
King Behemoth
Recommended: 75 with alliance
Behemoth+1... his big, bad, very nasty brother. Not only does he tower over you and attempt to squash you with his foot, he casts Meteor and attempts to one-shot you. Nasty.
Kirin
Recommended: 75 with alliance
The hardest HNM in the game. Average killing time averages from 3-6 hours; my linkshell clocked in at 5 on our first try. He is not for the faint-hearted, please go to the bathroom before coming to fight him. Manticore type mob, with a nasty temper. Does special attacks back-to-back. Fun.
TEH toughest puppies
These kids make Kirin look cuddly and cute, have longer spawn times, and generally kill your alliance by snorting at it.
Tiamat/Jormungand/Vrtra
Recommended: 75 with alliance
The three new dragons included in the CoP patch. Each have their own special techniques; Tiamat flies into the air and shoots fireballs, Vrtra spawns undead stuff to try and pwn you as you try and pwn him, and Jormungand -- well I haven't encountered him yet. ^^;