Well, as stated in the title, I have an idea for two bosses. And a bunch of items, including summoners and drops.
A wyvern with dark hues of blue and green. The eyes are completely azure-colored, and they leave a trail of same color. Both eyes and trails illuminate. It is meant as a preparation boss for when you want to fight wyverns and earn souls of flight. Upon defeat, it drops a few shadow scales, some demonite ore, and a medium-large amount of coins. It's attack strength and defense is lower than a normal wyvern, but it is more tricky. It can turn down instead of only up. Summoned with an item idea, a gale, made out of an entire stack of feathers, to keep veterans from abusing.
Not as much like a wyvern, but more like the dragons you normally see in adventures. Really black scales with a small trace of blue, green claws and teeth to resemble mythril, and with crimson-colored eyes. It flies similarly to a demon until it lands on a fairly flat surface. While airborne, it can spit cursed flames from it's mouth like a clinger, or Spazmatism in it's first form. Once it is on a flat surface, it can fire a stream of cursed flames from it's mouth, similarly to Spazmatism in it's second form, but the head cannot turn while firing, so you got a perfect oppurunity. However, you can make it cease fire with too much damage at a time, and the stream is longer. The stream lasts approximately 4 seconds, and then it flies away again. If you touch it while it is moving, it causes quite a lot of damage, but while it is standing still, you can even stand on it's back (or head) without taking damage. It is immune to confusion and both types of fire, and it can instantly break ice from an ice rod. Upon defeat, it drops a huge amount of demonite ore, a small amount of mythril ore, a huge amount of souls of night, some souls of flight, and sometimes, very rarely, another item idea, an ice dagger, a powerful shortsword with the ability to freeze (which the DD is immune to). Summoned by dropping another item idea, a dryad voodoo doll (an uncommon drop from wyverns in the corruption), into lava on the surface. It must be incinerated, otherwise the DD will not spawn. The dryad will die, similarly to the guide and the WoF.
Please give feedback to improve the idea if possible. You might have seen quite a few non-chinese dragons.