Breeding them is fairly easy. The gestation period is about 3 hours. Once they are born you have to force feed them non-poisenous mushrooms till they reach about 1.0%. Their baby cycle moves pretty quickly. About 2.5% per hour est.
A good idea, while you cannot upgrade their attack, you can get a pack and upgrade their health and speed. They become useful as attack dogs this way. Another usage is to transport wood early game. Hope this helps!
Get one immediately! Passive tame with aquatic mushroom. It alerts to enemy players and creatures as well as keeps away the nameless provided its light is charged. Also get its health right up as mine finished off a level 70 raptor after it killed me and I managed to get all my stuff back