I have been trying to get the new espers in FF6.
But I am having some problems.
How do you beat the Gigantaur?
How do you get Gilgemesh?
Where is Diablos?
And How do you beat Leviathan?

Gilgamesh, Diablos, Leviathan do not show up in FF6 at all. They do however show up in FF8 do you mean that pheraps?

As for Gigantaur which I think is one of the 9 dragons in WOR. You are probably too low level or if I rememeber right don't have Float equiped which makes Quake and other eath spells miss. I forget which item gives Float as an Accesoary so you will have to look around.

He means in VI Advance, Reva. I can't honestly say, I haven't really played it since I bought it.

Ah that explains it I haven't played Advanced yet. Never mind.

I don't feel compelled to complete the extra content in the GBA ports, anymore. I finished Dawn of Souls (I & II), having done EVERYTHING and was disabused of the notion after having to repeat the 40 level dungeon in 1 because I had to fight monsters that only spawned on lava floors, below the 30th level to complete my bestiary. Did I mention the floor order is "random." Sure, I found a chart detailing the permutations, but that ended my desire to bother with such things. Sure, you know I'll do that kinda thing in main lineage games, but ports and spin-offs go relatively un-mined.

Edit: My this sounds like I'm talking out of both sides of my mouth. Shame on me. The truth is I have stopped messing with extra-lineage games and content because I have practical restraints on our time, and I have to draw the line somewhere.

I have been trying to get the new espers in FF6.
But I am having some problems.
How do you beat the Gigantaur?
How do you get Gilgemesh?
Where is Diablos?
And How do you beat Leviathan?

The Gigantaur's esper name is actually Cactaur...I think. You can get him by wandering around the desert strip near Maranda and killing 10 cactaurs. Be careful, though...if you can't beat Leviathan, you're going to have BIG trouble with this guy, because he hits multiple times (3 or 4 at once, usually) with Thousand Needles (1000 damage each) and retaliates with some kind of attack which does over 2000 damage usually.
By the way...just noticed this, but cactaurs seem to appear in one specific space...maybe I'm just seeing things, but this seemed to be the case for every cactaur I killed. And also, those big monster thingies which appear in between cactaurs are weak against ice and water.

Gilgamesh costs a lot. You should be able to get him if you wandered around in the Maranda desert enough, as each monster there gives you 10k gil...you go to the auction house, where lots of weird stuff is sold. You can ignore the stuff if you don't need it or don't have enough money (500k gil) for Gilgamesh, or you can buy them. Your choice. A weapon called Excalipur eventually shows up, and you can get it for 500k gil (don't equip it! it sucks). Then you can go to the Colosseum and bet the thing for some item which is cool on its own too. But after you beat the Onion thing, you have to boss-fight Gilgamesh (with all the characters you brought, not just the one fighting in the Colosseum). He's kinda maybe hard-ish. I only fought him and Cactaur in the CES challenge, where I had way amazing set-ups, so I don't know...seemed easy to me.

Diablos, you won't be able to get until you beat the game. It's a long, long story. You have to beat the Kaiser Dragon at the end of the Dragon's Den to get it. I haven't been able to get it yet, so I don't have any tips in this area....

Leviathan...was pretty easy, and I don't think Flood (the spell you can learn from it) is all that powerful. But anyways, you can find him by traveling on the one and only ship in the game, the one that goes to and from South Figaro. Leviathan attacks with really annoying all-hitting attacks of water, and also attacks with even more annoying retaliations. So make sure to only hit this guy with REALLY strong attacks, and to have a good healer around. Remember, he's weak against Lightning, so Thundaga will work quite well (if you're far into the game, doublecast Thundaga for even better effect). That's about all the tips I can give on him.

Just remember, GET STRONG before you try any of these bosses...they're all frickin strong. And annoying. It's a wonder I can only beat them in CES challenge...strange me.

I have been trying to get the new espers in FF6.
But I am having some problems.
How do you beat the Gigantaur?
How do you get Gilgemesh?
Where is Diablos?
And How do you beat Leviathan?

gilgamesh will probably be the easiest for you to obtain because you can just physically destroy him. the others take some pre planning.

with gilgamesh, you're going to need the excalipoor...you can get that at the auction house. talk to the guy in front of the house that says he heard that a rare sword was for sale. then go in the house and talk to the guy to let him know that you want to be a part of the auction. sit through about a billion of those auctions for the ships and talking imps, etc. and finally the sword will be for sale. take that sword and bet it in the coliseum. you'll fight an onion knight. win that fight and gilgamesh will pop up. defeat him (he is strong, so be careful.) and you win the esper. it teaches you quick and valor. it gives + 2 strength upon leveling up.

leviathan is the second easiest. some might say the first. you need equipment that is going to give you protection against his flood attack and all the other stuff he dishes out. prepare for that by buying the according equipment. you can find leviathan if you ride the boat between south figaro and the other town...i forgot. just find the town with the boat and get on it. PREPARE and save before this.

gigantuar...defeat 10 cactuars and then he should show up. some say the southwest portion of the desert outside of maranda, but he showed up in the middle for me. he is HARD if you don't know what you're doing. reraise and a dragoon is a must unless you can handle 10,000 total needle attacks + the other needle attacks he will randomly dish out at you. cast golem, fenrir and reraise on everybody. your dragoon should jump every round. everybody else should be hitting him with the hardest stuff they have. when he dies he will spam 10,000 damage total at the party. your dragon should be in the air and your ppl should have reraise cast so you'll be ok. if you aren't at a certain level it will be harder because you won't be able to keep reraise up after he hits you with 1,000 needles normally (before he dies). good luck. its not THAT hard but the first time you see this you'll be like "...the fuck??!" lol.

you get the cactuar esper and it teaches teleport, vanish and hastega. it also gives a speed + 2 bonus.

diablos you need to beat the bonus dungeon to get. its very tedious...i'm on like the 5th or 6th dragon now. i lost count, honestly. not only that but there are other enemies and bosses in this dungeon. i hear that diablos gives a 100% hp increase upon leveling up but i'm not sure if it teaches anything.

*snip*right. flood fucking sucks. not worth it at all. if you can beat leviathan, you already have ultima. ultima trumps anything in the game outside of quick, curaga, reraise, golem, fenrir and zona seeker. flood is laughable, but for the sake of completion, all my mages know it.

the dragons den is pretty boring. some of the fights are easy, the enemies are really easy but the other dragon fights are intense if you don't know what to do. things like outlasting an enemy by letting them basically throw everything at you til THEY run out of mp is crazy. some of these guys have an hp loop, so if you kill them they can come right back. i'm like level 77 though, so i'm good, but this shit is really tedious...the whole split your party into 3. if you don't have at least 9 characters that can debo any and every living thing in the game, don't enter the den unless you want an insane challenge.

the tediousness (is that even a word?) is a challenge in itself. the puzzles + random encounters. eh =/ word of advice to the thread starter...train in that desert with the cactaurs/sand worms and the dinosaur forest for money. you're gonna need 99 of a lot of stuff, just in case. also you need gaia gear (4), genji shields, paladin's shield, master's scroll, soul of thamasa, etc.

Thanks guys!