http://paizo.com/threads/rzs2q9f7&page=3?The-ARG-race-restriction-and-favored-class#147Related Point: Can I have an 18th-level animal companion at level 12?
A character’s effective druid level for determining the abilities of her animal companion (based on Table 3–8 on page 52 of the Pathfinder RPG Core Rulebook) cannot increase her animal companion’s Hit Dice above her actual character level + 1. An animal companion receives no additional abilities for its level unless it has the requisite number of Hit Dice; a character can increase her effective druid level further, though these effective levels do not grant any benefit until the character’s actual level increases. For example, a 12th-level aasimar oracle with the nature mystery and the bonded mount revelation could theoretically have an “18th-level” animal companion; however, her animal companion would only be “16th-level” for all abilities because the animal could not have more than 13 Hit Dice.
