Slugma
The Lava Pokémon
Type: Fire
Official Registration #: 218
Entry: The body of this small, slug-like pokémon is made entirely of lava, and as such, it must be constantly moving. If it stops even for a moment, its body will cool and harden to the point where its “flesh” becomes brittle and breaks off easily. Unlike with other pokémon, these separated chunks do not form their own beings and cannot be reintegrated with their mother slugma. Rather, they remain independent pebbles, and the slugma itself simply grows smaller until its entire mass shatters. As one can imagine, slugma is also incapable of falling asleep for long periods of time due to the risk of this exact process happening … which means many trainers who don’t entirely know better face an unfortunate bout of tragedy whenever their slugma are exposed to sleep-inducing moves.
Magcargo
The Lava Pokémon
Type: Fire/Rock
Official Registration #: 219
Entry: The evolved form of slugma, by battle experience. The shell on its back is actually a bubble of its lava-like flesh, solidified on the outside by its slightly cooler temperature compared to the rest of its body. The interior is actually hollow, and as such, it can shatter at the slightest touch. If anyone is curious as to why de-shelled magcargo are not common, it may have something to do with the fact that the average body temperature for this pokémon is over 18000 degrees Fahrenheit, making physical contact rather complicated.
The Pokédex According to Bill 