My daughter got as a present 3 figures which belongs to a collection of characters from La Granja de Zenón or Zenon the farmer, which is a very popular cartoon from Argentina (and Spanish speaking countries in general, you can watch it in Prime Video as well 
). Besides the figures (full collection is around 12 figures), there is a music box which works similar to the Toniebox, in the sense that you put the figures on top and a song starts playing. It is a much simpler mechanism, as there is only one song per figure, and all songs are stored in the box.
Unfortunately I could not find the box or characters in Europe, only in Argentina (I will get a few more when I visit my family ).
I couldn’t get hold of a box myself, but I thought that the figures could be modified to be used with a Toniebox rather easily, and indeed that was the case!
After a bit of trying and using quite a bit of force, I was able to open the small lid at the bottom of the figures, where I found the existing RFID tag.
I removed the tag and replaced it with a SLIX-L Tag from RFIDFriend. I ended up putting it on the figure side instead of the lid, as otherwise it was too close to the Toniebox. I also tried adding a magnet, but due to the narrow space inside the figure, only a 1mm thick magnet could fit (maybe even a 2mm would have fit). After some trials, I finally decided against the magnet, the figure is too big and heavy and it didn’t hold on the box if I tilted it, plus I got some interference with the RFID tag.
I really like how the figures seem almost made to be used with the Toniebox, and my daughter really likes listening to her favorite Zenon the farmer songs from those figures!