You have gone s-s-s-soft!
— Scalestro to Dr. Colosso
Scalestro is a supervillain from the Villain League. He worked with King Crab and Lady Web to trick Dr. Colosso so that they can kick him out of the villain league. Scalesto is portrayed by Scott Vance.
His costume is a thick layer of reptile scales.
In A Hero Is Born, Scalestro is one of the villains who welcomes Dr. Colosso and Max into the Villain League headquarters. After King Crab reveals their plans to trick Dr. Colosso so that they can kick him out of the league, Scalestro says that Dr. Colosso has gone soft. Max makes fun of the way he pronounces "soft" and defends Colosso telling him that Dr. Colosso is as evil as they come. But the villains don't buy it. After Max is captured, Scalestro goes up to celebrate along with King Crab and Lady Web. He's also one of the villains who later show up when King Crab is defeated by Phoebe and Max. He quickly gets knocked out by Hank Thunderman.
In Thundermans: Secret Revealed, it is revealed that Scalestro has a son who goes by the name "Son of Scalestro." Son of Scalestro works for Dark Mayhem and has a similar reptile scale as his father and also hisses when pronouncing "s", almost like his father.
- Scalestro hisses when pronuncing "s" sound.