I'm thinking about making the tail actually be something that secretes poison, something akin to a scorpion tail. That way, I have a reason as to why the tail looks like that. Maybe they could swing their tails to splatter poison on predators to defend themselves? The poison itself burns on contact and may kill if ingested.
Also, I guess the species in my anthro world could use the poison to coat weapons and such. I can see an assassin pallio using the poison to kill a target.
Edit: 1/11/14
This species is now called a Spriven.
Facts:
Diet: Omnivorous. Eats a large variety of things, such as plants, leaves, small mammals, birds, eggs, insects, fruits and nuts.
Lifespan: About 10-15 years
Size: Raccoon sized. May weigh up to 30 lbs (14 kg)
Habitat: Forests, riverside, urban areas
The spriven is a small plantigrade mammal. They are usually solitary animals, but a small group of spriven may be found sharing the same territory. A spriven can often be found scouring the area for food or climbing trees.
They have a long tail that resembles a brush. From the tip of its tail, the spriven secretes a black viscous venom. When in danger, the spriven will whip its tail at its attacker, sprinkling the venom all over it. The venom burns and is capable of killing in large amounts or if ingested. The fur of a spriven is special in that it is immune to the venom.
The venom may be carefully harvested by using special gloves made of spriven pelt. It is often used to coat weapons or to create deadly poisons. The pelt of a spriven may be harvested for its immunity to poison.
Marking/color guide:
The spriven is based on a red panda, so it's color and markings a little similar to one.
Markings: Each spriven has the same type of markings:
Link to marking guide
As the guide shows, each spriven has a light colored neck, tailtip, and eyebrows and dark colored legs, three back stripes, and a mark that starts from the bottom of the eyes and extends to the cheek. The dark markings may vary in length. The leg marks can go from the tips of the toes, to the top of the back, like a panda. The 3 stripes may extend all the way down to the belly, or stay short. Each stripe may be a different length. Play around with the lengths 'til you find something you like!
Marking Colors: Each spriven has a color scheme of 3 colors only, light, medium, and dark, as shown on the guide. Spriven come in shades of reds, oranges, browns, and creams/whites. Examples can be seen in the oekaki above.
Eyes: Eyes are only yellows and greens.