
The Gumberoo - Fearsome Critters (1910.)

Fearsome critters (1939.) The stove-shaped Gumberoo - its 16 extra "rubber feet" would be used for boots.

The Gumberoo - (2008) Richard Svensson.
The Gumberoo (Megalogaster repercussus) is a fearsome critter told by the lumberjacks of emerging America in the 19th and early 20th centuries used to explain sudden forest fires.
Description:[]
The Gumberoo is said to look like a fat black bear in shape completely hairless except for its prominent eyebrows and bristly hairs on its chin. Instead, it has dark, smooth, and extremely tough coal black, leather-like skin. This makes the beast invulnerable to bullets, rocks and arrows. Anything shot at the beast would simply bounce off.
its main weakness was said to be fire, the scarcity of gumberoos was perhaps due to their combustible character and the prevalence of forest fires. The animal burns like celluloid, with explosive force. Frequently during and after a forest fire in the heavy cedar near Coos Bay, woodmen have insisted that they heard loud reports quite unlike the sound of falling trees, and detected the smell of burning rubber in the air. When the creature was photographed, the photos negatives would explode as well.
The Gumberoo was also said to always have been hungry and devoured anything it can find that looked like food. A whole horse may be eaten at one sitting, but it's not enough. fortunately, is not swift in its movements or annoyed in the slightest degree by the presence of enemies: A gentle giant.

Gumberoo as it appears on the "the hunter the tick and the gumberoo" (1971)

as it appears in GWOT! (1967) https://archive.org/details/gwothorriblyfunn00mend/page/34/mode/2up?q=gumberoo

Fearsome Creatures - (2015.)

Gumberoo as it appears in "Ol Paul the mighty logger" (1976)https://archive.org/details/isbn_9781442002951/page/98/mode/2up?q=gumberoo

Gumberoo - as it appears in Curious critters (1969)https://archive.org/details/curiouscritters0000laub/page/26/mode/2up?q=gumberoo
in the 2015 horror inspired "Fearsome Creatures" the Gumberoo has thirteen limbs, ten arms and three legs. Its diet is omnivorous physically and literally. The bear is NOT a gentle giant. After being burned, if a human inhales the particles of the beast, the organs will get coated with rubber, which is easily misdiagnosed as tuberculosis. Its natural enemy was said to be The Timberdoodle which clamps down its teeth and will not let go until thunder is heard, is the second weakness of the Gumberoo and the only animal the bear fears. Because of this, the Gumberoo is a coward when its rubbery skin is bitten. - Its scientific name is Triskaidecapus elastica.
Habitat[]
Gumberoos make their dens in the bases of huge, burned-out cedar trees along the Pacific Coast from Grays Harbor to Humboldt Bay. The creature spends most of its time in a state of hibernation, only leaving its lair a few times a year to search for food. When active, the gumberoo is always hungry and will eat any living creature that crosses its path.
In Popular Culture[]
Gumberoo as featured in MetaZoo: Cryptid Nation
Further reading[]

Gumberoo how it might look IRL (a bear with mange, lost all its fur.)
"The Gumberoo" from Fearsome Creatures of the Lumberwoods (1910) by William T. Cox
"The Gumberoo" from Fearsome Critters (1939) by Henry H. Tryon