No, they are harmless
Go to google and search bearded dragons, all of the pictures will be adults.
Bearded Dragons usually attain full size in 3-4 years. Obviously this depends on how much food they eat, and how often - as this will vary with each reptile.
If the bearded dragons are the same sex and have grown up together yes, if not no.
A fully-grown Bearded Dragon CAN be as much as 14 inches nose-to-tail. It's rare for them to get to that size though - the 'norm' is around ten inches.
Your bearded dragon will become fully grown regardless of the size of the enclosure, provided you properly meet its needs for food, UVB, heat, and hides, but a MINIMUM of a 60 gallon sized tank would be recommended for the adult lizard to be free of stress and have enough room to be comfortable. Bigger is, of course, better.
the whitetailed deer
Komodo dragons are fascinating creatures and they can grow to weigh 300 pounds or more. In terms of length a fully grown adult can grow to 3 meters which is about 10 feet.
Well if they are both babies yah but if grown they will see who is the alpha lizard
NO, only a FULL GROWN dragon can eat pinky mice. That is IF they will even do it then. Look at the pinky and look at the size of the baby dragon's mouth... do you really think it would fit?
they are fully grown when they are 6 years old
The term juvenile, when refering to reptiles specifically the bearded dragon, is any stage in between when he is still a baby (Under six inches without tail) and when he is full grown, (aprox twenty inches without tail). so there is a fairly large size range for your beardie to be still considered a "Juvenile*
no. a maltese is fully grown at one year of age