Not quite as large as a most dragons, the Blue loves to fly or burrow (half speed) and can ambush from either the sky (where theyre almost invisible) or the ground (where their burrowing tends to give them away - a train-sized object going under your feet is something even a drunk would notice).  They are, however, VERY patient. If you can get a Blue Dragon to give you its word, it will abide by the letter of the agreement.  Blue Dragons would (almost) rather have you as a slave, than as dinner.