How to get these avatars:

Pirate:View profile of pirate pet that you own
Purple:View profile of purple pet that you own
Pink:View profile of pink pet that you own
Lela:Attach a lela to your pet
Starry: Have a starry pet play with a rarity 7 or higher star
Mermaid: Feed a piece of sushi to a mermaid pet (ANY pet)
Digital: Have a pet turn into a digital equilor from portal
Operation Portal: Random while doing operations portal
Radioactive: Use a radioactive costume on your pet
Happy Birthday: Feed your pet a three years cake (at least that's how I got it)
Undying Festival: Complete the undying festival
Grave Robber:Rob a grave and get bones
Devil:attatch a staff of the devil to a devil pet then view it
Invisible: Look at the profile of the pet named invisible
Maramail: Look at the profile of the user maramail
Eleka Prison: Feed a minipet at Eleka Prison
Arrrgh: Fix your marahome with the wrong tool or use a tool on it when it's not broken at all
Trick or Treat 07:
Trick or treat with Elgor