Named for the Roman messenger god, the Mercury Dragon has long been a carrier of messages from island to Dragon Island. While this is a noble and useful purpose, many dragons consider Mercury Dragons to be a bit gossipy, and they are rarely trusted with intimate secrets.
Mercury Dragons are excellent messengers - but only for a one-time purpose. Very rarely will a Mercury Dragon return to its original roost, choosing instead to continue delivering messages to anyone in need.
Evolved Mercury Dragons are relied upon to deliver messages to any dragon at any time. Some are even called upon to deliver letters to destinations in space; none have been successful, of course, but not for lack of trying.
Mercury Dragons are able to deliver messages at amazing speeds.While in route to a delivery, they are even able to break the sound barrier, often delivering a message before recipients can hear them coming.
When a breeding pair contains Diamond and only one other non-minor color, you can get a pure dragon of that color or a Diamond hybrid with that color if any are possible. This means that when the 墨丘利龍 is paired with a Water Dragon, the most common result will be a Water Dragon, with an extremely rare chance of a 墨丘利龍.
When a breeding pair contains Diamond and at least two other different colors, Diamond is then treated as its own color under normal rules and any possible offspring within that color pool can emerge. If a 墨丘利龍 is bred with a Magic Dragon, for example, you could get any hybrid dragon with a combination of Blue, Purple, or Diamond colors. If you have 4 or more colors in the pool, you can also breed a pureDiamond color dragon.