okay so here's a small mod where a chibi Mikue Hatsune (r) can be your starting pet.

https://drive.google.com/file/d/0B2aVtkeuHrtccjNWMmlTQlpjREU/view?usp=sharing

i found this 3d model online.  It was in .DAE format which can be imported into Blender using the File > Import > Collada option.

It had no rigging that I could see, so i imported the standard Hum_F mesh to see if I could use the standard female TL2 skeleton for Miku.

After cleaning up the mesh (took away several pieces which would not be seen much anyway in the game) I parented it to the TL2 skeleton with Ctrl+P and the "with empty groups" option.  Of course it did not deform with the skeleton right away

So i did the assigning of vertex groups to the bones in the TL2 skeleton.  I selected mesh faces in logical groups (head, chest, right upper arm, right forearm, right hand, etc.) then selected the bone to assign it to in the bone list in Blenders armature window.  The mesh started deforming with bone rotations!

So I just kept assigning vertex groups to to bones until the resulting mesh deformation looked okay.  It can still be better, but I was so pleased with myself I decided to make this pet mod! XD

EDIT:

First version had trouble with the custom pet sounds.  Updated the link above to point to a newer version

Thanks very much @Sch123 ! and thanks also for the link

EDIT:

If anyone would like to play around with the Blender files, I've attached those below

Ey @Aherin it could be a pet, it could be an armor set too     

I'd be willing to do it too! Just don't expect it too soon k?

I get another site, maybe this can also give some new ideas 

https://free3d.com/
https://www.yobi3d.com/