ieatwyverns

I recommend you both bring dragon attrib. Weapons, i'll make your lives easier. Make sure to use the dragonator. Drop the gate on it and fire all ballista and cannon shots you can get your hands on, at it.

When it fires a fireball at you, run to it's leg and hit it two or three times in the leg then run away again.
If it flies up into the air, get as far away as you can, then the fireballs it tries to fire at you are out of range. and keep trying, you maybe won't do it the first couple of times.