I collect Harmony Kingdom, figurines made of marble resin in the UK by a few artists. Many are boxes such as this one and often there are a variation, either mold or color.

This is Terra Incognita...no variations on this piece by David Lawrence.
Many of the pieces have hidden 'secrets' and a bit of British humor especially the ones done by Peter Calvesbert.

"S e c r e t s

This group of five wild horses was sculpted in celebration of the spirit of both wild horses and frontier people. The horses are bursting through a fence as they break down a “No Trespassing” sign. “Terra Incognita” is inscribed on the base. Inside . are a raccoon, a riding boot, a blanket, and a Trilby hat with a 10/6d price ticket from Alice in Wonderland’s Mad Hatter. A hidden cooking pot is found under the interior hat’s screw top lid. Hallmarks include ©, heart, HBC logo, ed.#, and DL."