It is common for humans to burn candles or incense to drive away foul odors, but even large fire pokemon such as Infernape struggle to burn away Stunky spray, Gloom pollen, or the many other weapons used by poison pokemon to clear their surroundings. This is not because their fire is insufficiently strong, but because these pokemon have a time limit in the form of their own nose, and before long will flee back into their pokeballs, or if wild run as far away as possible. It is for this reason that they turn to the Skuntank.
Skuntank fire is not unique in its effectiveness, but in the fact that it comes from a poison pokemon accustomed to a stench every bit as foul as those it seeks to dissolve: its own. Although an angered Skuntank can make even Stunky run away, Skuntank refuse to spray for prolonged periods, and in the wild will often burn away the smells of their own children to keep peace in their habitat; as fewer survive to adulthood, more lands have been lost to the stench of Stunky.
This is not, however, to say that Skuntank are kinder and gentler than their younger counterparts. Skuntank are nearly as greedy as humans, and will demand vast ransoms in food before agreeing to burn away any smell – a ransom which even starving peasants would sooner pay than risk losing next year's harvest to the smell of their fields. The Skuntank themselves, like Honchkrow, are often the very pokemon responsible for the problem they seek to solve, and many in Sinnoh have wondered if all dark pokemon engage in extortion. It is their extorted pay which accounts for their greatly increased size and enormous tails, for Skuntank never stop growing, and the tail grows fastest.
