The Big Bad Wolf is a one-time villain from The Powerpuff Girls comic book franchise, only appearing in the issue, "Bedcrime Stories". He is a fictional fictional villain, portraying the big bad wolf from the story, Little Red Riding Hood. His role and personality constantly changes inconsistently because his story's narrative is always being altered by the girls.
In "Bedcrime Stories", Professor Utonium told the girls the story of Little Red Riding Hood. In the book, the Big Bad Wolf crept up behind Little Red Riding Hood and tried to kill her. The Powerpuff Girls interrupted the story to say that Little Red Riding Hood used her untraviolet superpowers to beat the wolf up. The Professor told the girls that is not what happened and continued the story, normally, saying that the wolf asked the little girl for her basket full of goodies and got rejected.
Buttercup contributed to the story, saying that the big bad wolf was actually an evil scientist, who kidnapped Little Red Riding Hood and trapped her in a torture machine called The Agonizer and electrocuted her with it.
Bubbles argued that this was not how the story went and continued on to say that the wolf turned out to be a good guy and became friends with Little Red Riding Hood.
Blossom interjected, saying that the big bad wolf was in fact an evil spy, who worked with Little Red Riding Hood, who was also an evil spy. They planned on infiltrating Granny's house and stealing all of her money and priceless objects. In Blossom's story, the wolf enters Grandma's house and approaches her with a bat. Bubbles worriedly asks if the wolf hurt her and not wanting to hurt her feelings, Blossom changes the story to say that the wolf actually just sent Granny on a vacation, to get her out of the house.
After getting Granny out of the house, the big bad wolf wanted to keep all of her loot to himself and not share it with his partner in crime, so he dressed up as Granny and lured Little Red Riding Hood into the house so he could eat her. While attempting to eat Little Red Riding Hood, a nearby lumberjack heard her screams for help and came in to beat the wolf up.
The wolf transformed into a karate-fighting ninja and defeated the lumberjack but then, Buttercup's self-insert character came in and beat the wolf up. The wolf transformed into a giant crab-wolf hybrid monster called "Wolfor the Terrible" and Buttercup turned into a Shogun warrior and fought with him. Blossom and Bubbles told Buttercup this was not how the story ended and Buttercup asked Professor how the story really ended. However, Professor Utonium had fallen to sleep, so he never told them how the story ended.