Squiggles is a one-time villain from Powerpuff Girls Z, the anime spinoff of The Powerpuff Girls, only appearing in the episode "Gigi the Great". Squiggles is the companion cube of Gilbert, who was initially a harmless and lifeless teddy bear, but after being struck by Black Z Rays, turned into a villainous and domineering demon toy.
Gilbert referred to his teddy bear every time he was in a time of distress. He'd always mope around in the bathroom with it and complain about his problems to it. After asking it a question, Gilbert would pull a string on it, making it return a generic response such as "I love you" or "You're my best friend", which always managed to give Gilbert just the reassurance he needed to pick himself up off the ground and get through the rest of the day. As stupid as this was, it was still completely harmless.
One day, Squiggles was struck by Black Z Rays, which turned it into an evil toy, that would give Gilbert bad information and also turn him into a mutated villain, known as Gigi the Great. Squiggles gave Gigi hypnotic powers, which led him to give his customers bad haircuts, only for them to be met with praise.
After Gigi lost a war with The Powerpuff Girls, the latter party learned that the source of Gigi's villainry was coming from the teddy bear. They took the teddy bear back to the lab and got Ken to perform some modifications on it, turning it into a better influence on Gigi.
The next day, Gigi sought confirmation from Squiggles, but Squiggles responded to all of his complaints with new sound bytes from The Powerpuff Girls, telling him to quit his bellyaching and start acting like a normal person. This caused Gigi to throw a temper tantrum, but he eventually got over it and started acting like a civilized human being, albeit only for the rest of the episode.
Unlike Gigi the Great, Squiggles never made any reappearances in future episodes. Rather than accompanying his master/minion, the idea and concept of Squiggles had seemingly been discarded by the writers, completely.