The "dragon" (let's call it that) need not be negative.
1. It may be an entity (and thus, it may be trying to protect you or show you something).
2. It may be symbolic (e.g. represent something you need to do).
From the information you've given, I suspect the latter. The trick now it to find out what it represents. Only you can know that.
I found your comment on meditation interesting. If your mediation is passive, then it is almost impossible to "do something wrong" (although it may bring out negative emotions or thoughts, which can then be examined and dealt with). If the meditation is active (meaning you are trying to call/activate an entity or energy), then yes, care should be taken.
Hope this helps and good luck.
