Immediately, Nigel's ears pointed, almost becoming bat-like.
Then, he got a third eye on his face. His teeth became long and sharp.
There was a sudden loud rip, as a huge long green lizard tail sprouted from his behind, splitting a huge hole in his slacks.
Nigel saw his toes burst from his hiking boots, as his feet expanded 3 shoes sizes bigger, and sharp claws grew in place of his toenails. and his hands gained the same sharp claws as well.
And then, Nigel grew, to double his size, splitting his clothes to scraps, and then, his skin turned a pale lavender, and his hair turned a vibrant neon blue.
"Honey?" Wilma said, gobsmacked at the beast that was her husband. "Is that you?"
"Yes, it's me, honey." Nigel said, smiling with sharp teeth.
aLMOST IMMEDIATELY, Billy noticed the scraps of his father's clothes disappearing. "Dad, your clothes!"
"Don't you worry bout them, son." Nigel said. "When people become monsters, their clothes disappear, or get destroyed as they tf." "But do not worry." he added, "the clothes magically return to their owner's homes, as if they were never destroyed to begin with."
Nigel noticed the spot on his crotch where his dick used to be - his dick had gone, replaced by a vagina. [He had failed to take into account that when males became monsters, their penises were removed or changed into vaginas.]