Wear a lure bracer, like karlabaines has already stated and that large leaping dragon is called Elder Drake, if I'm not mistaken. To beat the elder drake, you will need a very high rate of evasion, preferably Berserkers with the ability Evade and Counter. This way they will avoid all physical attacks towards them, and always a White Mage to be on the safeside and revive any characters who are hit by the oversoul move, Pyreflexi.
However, if you line up close to the opposite wall, and wait for it to jump backwards, running quickly across the opening will result in you not having to fight the drake at all, though the rewards are quite tasty.
Other than the Via Infinito, try maybe the Thunder Plains, I believe they have a few nasty monsters running around by them. Hope I helped.

~*Crystal