COW #262: Armuro

My entry to Conceptart.org's C.O.W #262: Ninja Companion. The description for this little guy is follows:

Armuros are small creatures capable of rolling into the shape of a sphere. They have two states; dormant and active. When dormant they retain their spherical shape mimicing similarly shaped objects, and their dark colouration helps with blending in to shadows, leaving them often overlooked (if they haven't already rolled away) when a fresh corpse has been discovered. Their active state can be triggered with any significant impact, causing them to unravel. Once unravelled the bulbous sensory organ at the tip of their snout detects heat, and causes the Armuro to project it's tongue quickly from it's mouth stinging the nearby target. Containing poison glands at the tip of its tongue, the Armuro injects its target with a large does of poison which spreads throughout the body, congealing their blood and causing death.
While in their juvenile state, the Armuro can be used to promote stealthy movement among practicing ninjas. Because the Armuro is so easily roused, its owner must learn to move fluidly and stealthily to prevent themselves from being stung by the Armuro while carrying it. While deadly in its mature form, the juvenile's poison is significantly weaker, leaving the poisoned individual bedridden for several days instead of causing death.

Thanks for looking!