Adult bunny dragons are anywhere from the size of an elephant to BIGGER. Since their spontaneous mutation, adult bunny dragons are capable of supporting up to three adult humanoid riders, if they're inclined to do so. Larger adults are, obviously, capable of carrying more.
Adults are, at this point, also able to take mates. These may be permanant matings or temporary ones. Once a dragon chooses a permanant mate, it may not take a temporary one, though temporary mates may later take permanant ones. Dragons may also, if they desire, choose not to take a mate. Most, however, see their duty lying in passing their genes on for at least one generation.
It should be noted that adult dragons eat a lot of food. Most will forrage their own food out of whatever vegetation is available, though this may cause problems for those who live in urban areas.
Only adult dragons can apply for budragism, the highly secular order of bunny dragon mages, who are able to wield the magic of their ancestors.