Curiosity Shop Set of 2 Glass Domes with Bases. Scary thing is that I actually have skulls already.
IKEA - HÄRLIGA, Glass dome with base, The glass dome with base can be used to display your favorite decorative items.
Vintage Taxidermy Butterflies Specimen by ThEeRabbitHole on Etsy
Antique Unique Skull & Skeletal Fragment Sculpture in a Victorian Glass Dome in Collectables, Animals, Taxidermy | eBay