Burrowl's original design resembled an Owl Bear/Moonkin, a creature from Dungeons and Dragons.
Burrowl and Magowl were originally intended to be part of the same evolution family, with a shared pre-evolution. The pre-evolution was never successfully created.
Burrowl is based on a Burrowing owl, in the sense that it lives underground in dry, arid places. Both Burrowl and Magowl were designed to have flightless wings, so Burrowl became a burly beast with digging talons.
Both Burrowl and Magowl were originally Great horned owls that had adapted to different biomes in an extreme sense.
Burrowl's name is a combination of burrow and owl.