Just as it says. I've seen countless rangers running around with unnamed pets, and I allways ask them 'Hey buddy, do you know how to name your pet?'. And their answer is allways something like 'You can name your pet?'.
So, just incase any of you are one of those Rangers running around with a Moa Bird, type in this little command:
where the 'xxxx' part is the desired name of your pet. This way that Moa can officially and properly be called Big Bird, like you know you have allways wanted him to be.