Saphira

Saphira is Eragon’s dragon, I don't know if cat years are mentioned in the text.

Saphira is first found in the forest while Eragon is hunting deer. He then brings her egg home but he thinks it is a stone. He thinks it is worth something. But then the traders come in and they don't want it. Later on in the book Eragon is in bed then he hears squeaking. Starteld he grabs his knife. After the squeaking has stoped he drifts back to sleep. ONce he wakes up the egg is shaking vilontly then drops on the floor. The starts to crack then out comes a dragon. Later on this dragon grows a mental connection with Eragon after he first touches her scales. Later on the dragon grows up and is named Saphira. Every day her connection with ERagon grows stronger.

the book does not mention how old Saphira is at all