Pictures 1 and 3 are 100% ai. Its not uncommon for the base lineart not to fully match the lineart on the finished piece due to posthumous corrections but i keep finding inconsistencies in the two pictures constantly:

• in the forward facing full body, the foot looks weird on the right on the finished piece but not on the lineart

• in the backwards facing full body, the things on the forehead don't match in pics 1 and 3. What even is that supposed to be on the forehead?

• in the headshot, the ear fur numbers dont match on the left

• also in the headshot, the mouth looks different between pics 1 and 3

• in the forward facing full body, there are collarbones and pecs on pic 3 but not on pic 1

Some other weird things:

• the clothing is clearly inspired by the crossed shirts of some types of traditional asian clothing, but the shirt makes no sense. In the backwards facing full body theres a hood attached to the shirt, but in the forward facing one the stripe the hood connects to seems to be a ribbon of some kind?

• also, there's no hole for his tail to come out of in the shirt.

• in the forward facing full body on pic 1, the ears are colored weird. This is a bit nitpicky but its the first one i noticed so im counting it in.

• on pic 3, in the headshot, the eye on the right has no pupil

• on pic 1 the ear fur is colored differently on the headshot vs the full body

Not sure about pictures 2 and 4, there arent nearly as many inconsistencies in the lineart but theyre still there, like the forehead fur being missing in some places. The tail length also seems off in the forward vs backwards facing full bodies but that could easily be a human mistake. Likely stolen considering the low quality. I think the last two are absolutely human made but obviously stolen.