@shemjm I’d grab some of the bone line from Reaper Minis and teach them the basics. Reapers has a large line of fantasy minis, so if your kids want something whimsical, it’ll be in there, and you should be in budget getting them.

As always, judge if your kids are likely to accidentally or purposely ingest minis before teaching.

There are also larger minis like dinosaurs that can be acquired through the 3d printing market. Not sure if the MLP painting figures are still around.