Everything here works on my own computer, but always use downloaded content at your own risk - and remember to keep backups of your original game files.
Here is another collection of (pretty sure) every internal texture in Petz 3-5 and Babyz! 99 Petz textures from the dlls, individual breeds and original clothes, and 155 Babyz textures from the Babyz rez.dll and the official downloadable clothes. All are in their original form and palettes, the only change I made is I marked a few Babyz textures which are different but have the exact same name as Petz ones (to hopefully prevent accidental overwriting).
Download Petz Textures | Babyz Textures
Full size blank bmps extracted from all of the original playscenes in Petz 3, 4, 5 and Babyz!
Single extracted images for all of the original clothes and toyz items in Petz 4! Stick them in your Resource\Toyz and Resource\Clothes folders to easily find an item, or great for visual people when you want to hex a toy or clothing item but aren't sure what would be best to base it on.
Disclaimer: I just used what I have in my game for these, I think it's complete but apologies if I missed any or if anything non-original snuck in.
Download Clothes Sprites | Toyz Sprites
Right Click -> Save just the ones you'd like, or download the whole set including the PSD master file with color-picking layers to coordinate with your photos.
You will need an image editing program to use these, but then just layer the mat over your tiny pictures. Final image size should be 100 x 70 px for the original game frames, saved as .bmp, and color depth decreased to 256 colors (I made mine with Photopea and Irfanview, which are both free!).
Download Pack plus PSD Master file
Petz by P.F. Magic