I did a walk-through (for the early stuff) and a Review, so now it's time for me to talk about the coolest monsters in Monster Hunter Tri and 3 Ultimate (they share a lot of the same monsters, but 3 Ultimate introduced Japan exclusive monsters to the United States and Europe so to those countries some of the monsters are brand new unless you played one of the Japan exclusive games).
I would put pictures of the monsters but the only good pictures are on Monster Hunter wiki. Fan art does not count. And neither does concept art. Plus I simply am too lazy to worry about precise details like image origin. So if you want pictures (or video) just copy and paste the monster's name in the Google search bar (or whatever you use) and go to images.
Now to start this list I do so believe everyone knows about Rathalos. It's big, red, and breathes fire. Classic European dragon meets big red lizard!!! Anyway, Rathalos first appeared in the original Monster Hunter and has been in literally every game since. Plus there is a reference to the original fight against him (all Rathalos are male) in Monster Hunter Tri because in his opening cut-scene the music that plays when you fight him in the first Monster Hunter also plays during the cut-scene.
I guarantee that you WILL DIE the first three times you fight him unless you fight him in previous generation games. I know because I only played the Third Generation games and guess what? He slaughtered my character. It was one-hit kill. And whatever you do, do NOT under any circumstances use a Long Sword on him. Long Swords are USELESS on him. Again I know because every time I faced him I used a Long Sword because the Long Sword is perfect for me. I am a Long Sword pro. But BOOM!!!! Rathalos tore my character apart. Basically unless you play the first two Monster Hunter games killing him in Tri or 3 Ultimate will be IMPOSSIBLE. But if you get his parts you can make really cool armor.
Spiky armor, I might add. Almost the whole set is covered in spikes. Plus it's fire resistant. Just don't get hit by lightning while wearing it.
Here is another cool monster that I actually enjoy fighting: Gigginox!!!! This monster is famous for annoying players because almost all of his moves will poison your character. I enjoy fighting him, and I K.O.'d him on my first go. Besides, he kind of represents the constant need to prepare yourself for a particular encounter with a monster. Remember when I said that Long Swords are USELESS on Rathalos? Well I strongly recommend that you DO use a Long Sword when you fight him for the first time. I really need his armor. Not only does it have decent defense (assuming you are crazy enough to not upgrade it), but wearing the whole set will negate poison attacks which I actually need because every time Rathalos kills my character it's either with a fire-ball (I'm okay with being fire-balled to death) or that annoying attack he does where he hovers in the air and swipes his toxic talons. It both poisons and stuns.
Anyway, Gigginox armor makes your character look like a vampire. Which is ironic because I consider Gigginox to be the Vampire of Monster Hunter. He reminds me of a vampire (a LOT). And vampires don't exist in real life. They only exist in the world of fiction. Anyway, my point is Gigginox is iconic. Almost as iconic as Rathalos.
Here is another really cool monster: Zinogre! This monster used to be Japan exclusive but was introduced to the American audience in 3 Ultimate. It reminds of a cross between Four Tails from Naruto and and a werewolf. The werewolf part from it's howling, the Four Tails part from the fact that is generally looks like a gorilla with a tail.
I have seen pictures of the Zinogre armor and I literally can't describe it. It's........Blue. That's the only way to describe it. It's so cool and unique I can't think of a way to describe it.
Now here are two downright adorable little fellows: Cha-Cha and his 3 Ultimate exclusive partner in crime Kayamba!!! Now they are a species of sapient monsters known as Shakalakas (I dare anyone to not think about how silly that sounds when you pronounce it). They are your character's sidekicks/apprentices/meat-shields/minions (whatever. All those titles have the same meaning). You can customize them with masks (they ARE Tiki-men after all) that both change their abilities and how they speak. Pitfall masks make these two speak like they are in the service and are in a heated gun-fight, but also transform into Pitfall Traps if you give them "the signal". The Ancient mask makes the wearer behave like a elderly man with a mild case of arthritis, but enable your character to breathe underwater indefinitely. the Grill mask makes Cha-Cha constantly talk about food, cooking, or eating (sometimes all of them at once).
Oh and you can fight Shakalakas in one of the Monster Hunter games (I forgot which one) but sadly you can't carve them because as soon as they "die" they instantly get back up and take off, but they leave a shiny drop item behind when they retreat.
This next monster is Japan exclusive: Goa Magara!!! Goa Magara is also a Fourth Generation monster, which means you can ride on his back like a rodeo. Goa Magara is basically a walking disease, as it infects EVERYTHING with the ultra contagious Feral Wyvern Virus. A Wyvern is basically another name for Dragon. Anyway Goa Magara also infects other monsters with this disease, and while it weakens Felynes and Hunters, it powers up monsters. But the real reason it infects them to begin with is because every monster has a place in the monster food chain. And Goa Magara is the vulture of the that food chain. It feeds on whatever the infected kill. Basically Goa Magara is lazy. He is too lazy to fight his own fights so he infects everything with Feral Wyvern Virus and watches the chaos ensue.
His adult form is even worse. Shagaru Magara!!!!!! This thing is shiny and gold. And it can amplify the effects of the Feral Wyvern Virus a thousand fold!!!!! Oh and Feral Wyvern Virus is a fan translation, so when Monster Hunter 4 Ultimate is released in the West, Capcom will reveal the official name of the disease.
Speaking of which, do you know why the monster Nebelsnarf is called that? Because Capcom's localization team made a tiny mistake with the translation but I am not complaining. Why? Because everyone gets to make fun of how silly that name is!!! Seriously, if the name was cool (like Dire Miralis. Now that is a cool name) nobody would want to make fun of it. And the best part of a victory is mocking the monster's name. Unless, as previously stated, the name is cool (again, Dire Miralis is a cool name).
Anyway, the final monster on this list is actually my personal Third Generation monster: Dire Miralis!!! He is simply awesome. He spews lava, AND sits at the bottom of a lake!!! It's like they finally made something that can control fire and water!!!!! Alatreon has Ice and Fire (and Thunder and Dragon) but since when to fire spewing monsters like to swim?
And the ARMOR makes you practically invincible!!! The armor boosts attack power to max AND is almost everything proof. Me? I only care about Defense and Resistances but I will alter the armor to my.....specifications. Like including Speed Sharpener. I rely so much on Speed Sharpener I can't imagine doing a single slaying (or capturing) quest without it. But I also like raw damage. Love raw damage!!! Which is why I like using Long Swords and Switch Axes. I don't like using Great Swords. Way to slow. I might use it during like a "slay 20 Baggi" Quest but otherwise I rarely use it.
For pictures just Google the monster's name and click on images. I am too lazy to put up pictures of these monsters myself.