Originally posted by ViiRuzZ
Yes that was a custom avatar. You can do it if you have a custom firmware.

If it's not in the PS store then it's not custom, but you can still have a custom avatar with it thou.
No you can't, you can only re-direct your Avatar URL from the PSN Servers to your own local .PNG, but no-one else can see you have a custom Avatar online, just your PS3.
But in this case it's NOT a custom Avatar, it's on the PS Store.