A unicorn and a bear from the Ashmole Bestiary, created in the 12th or early 13th century in England.
The bestiary also has this to say, on "Fire-Bearing Stones":
"On a certain mountain in the east [note: this may mean east of Alexandria, Egypt, as the Medieval bestiaries appear to derive from a text written in Alexandria, the Physiologus], there are fire-bearing stones which are called in Greek terrobolem; they are male and female. When they are far from each other, the fire within them does not ignite. But when by chance the female draws near to the male, the fire is at once kindled, with the result that everything around the mountain burns."