Heart

Dragons are special as they have two hearts. If one fails, the other is able to pick up the slack. It is unknown when they got this second heart, but it helps many of them fly. Both hearts are in the chest.

Magic Sacks

Dragons have a special organ called the Magic Sack. It filters all magic out of their body and into the sacks, which will expand as they fill up. These can only fill up so far before needing to release some magic, or risk the sacks bursting. These sacks are often found in the neck, though they may also be found in the guts of some dragons.

Magic sacks in the neck often mean the deagon has a second throat that feeds into These sacks. This is for swallowing more magic, or ingredients for spells. There is often a flap in the mouth that hides his second throat when not in use.

Veins will come off the sacks and go to different parts of the body depending on where the magic is used. They may go to fangs so they can inject magic like venom, sometimes it goes to the pores on the skin, or to the end of the tail or Injection.

Every dragon with magic sacks has at least one that has an element built into the sack. This means Dragons are born with one element, but can have extra ones depending on if there are 2 or 4 sacks in total.