That is an Ahea avatar. If you want to see what other avatars you can use, go to Preferences, then to Forum Options.
There, you can see what avatars you can use.
There are some that are "hidden" meaning that there are certain things you have to do to unlock them.
But since you are new, you probably won't have any hidden ones yet (though there is a great amount of non-hidden ones you can use).
Remember to hit Select Avatar, towards the bottom, if you want to changer yours :)
Is the box around the name still red? If it is, that means the name is taken or invalid (you can only use letters and numbers, there can't be any spaces, no cuss words, and it has to be 15 characters or shorter)
If the name is available, the box should turn green and let you hatch the creatu.