Hell, like any other ecosystem, is vastly filled with different species including the most common demons and devils. Whenever anybody thinks of the word, people generally think of a place where human souls are punished due to their sinfulness and they're right. Hell is an afterlife where the souls of humans go if they breaks certain rules such as murdering another or being an atheist (according to Christianity) to pay for their misdeeds. The Inferno Spider is an arachnid native only to this particular afterlife but, has the ability to travel into the mortal world by catching rides on incoming demons or demonic spirits. In Hell, the Inferno Spider can reach to about eight feet in diameter by adulthood while in our world they can reach up to the size of a tarantula. They can create complex webs that are known to burn the flesh of anything living, except for demons. Inferno Spiders, on both 'dimensions', are solitary hunters who target the weak as a food source. They are ambush predators and tend to use magma-like venom to paralyze their prey. For demons, this venom can easily paralyze them for enough time to allow the large arachnid to feed, however for humans, the venom tends to turn their veins into liquid lava which kills them if untreated. Anti-venom is possible if frozen or froze to the point of become injectable only for human use. Demons on the other hand, can become immune after the paralyzing effects wear off.
Inferno Spiders, like said above, are solitary animals until mating season. During mating season, both males and females fall into a strange, ritualistic dance once in courtship. This dance can happen from hours to days until their mating ritual is over. Unlike most animals whom lay either eggs or have live birth, both the male and female explode after colliding with each other at the end. After the fiery explosion, eggs and sperm generate young Inferno Spiders within a few seconds creating instant birth. Predators, such as fire elemental Salamanders, wait until the explosion to feed. In the mortal world, this is a dangerous deal after mating season has began which can result in some body's home to burn down. Like said in the first paragraph, Inferno Spiders catch rides from demons or evil spirits into our world to either obtain prey or create a new breeding population. The only way to get rid of Inferno Spiders is by exorcisms made for their species or are eaten by a fire elemental such as the Salamander mentioned above.
Inferno Spider (shown above) infestations can cause serious problems in our world and must be dealt with before mating begins unless, you don't mind having your house burn to the ground. The two common ways on knowning there is one around is by a sulfuric smell or strange burning from air vents, walls, or unusual places throughout the house.