>>8277595I got them from eBay, a seller was looking to unload their stock to make room so they sold me them for cheap and even threw in two free ones that had small cracks in them.
I'm not sure of this type of display case has a specific name or brand since the listing had a generic title like "Acrylic Display Case For Battle Beasts Lego etc" but maybe if you Google something along those lines you can find some.
The top layer of squares is slightly taller than all the other squares so it's ideal for Battle Beasts who are taller than average like the Giraffe.