I honestly wondered how Creon would have reacted mugman's insanity with the ice cream man all in all trying to Kill him and with his mental breakdown? I would imagine it being super hilarious and heartwarming at the same time
Creon was actually aware of Mugman’s attempt to play sick just to have the day to himself. So she volunteered to stay home and watch over Mugman while Elder Kettle and Cuphead went off on errands. While doing some chores, she heard the Ice-cream truck jingle. Then she heard it the second time after a few minutes. Which was puzzling. And then after the third time, it was starting to get annoying.
When she came out to investigate, she only caught the sight of the ice cream truck driving away, with a more sombre jingle. After hearing about Mugman's confrontation, I'd imagine a conversation similar to this:
Mugman: "....um Creon? Was I too harsh?"
Creon: "Yes."
Mugman: *looks absolutely wrecked*
Creon actually follows Mugman to help him apologize to the ice cream man. When they found him, there was no truck chase. Creon happened to recognize the guy and from there, they traded small talk. Creon frequently sees the guy when she's out in the city. Unfortunately, the guy still spoiled the book ending.
Creon had to rip a feral Mugman off of the confused man. She carried an angry, sobbing Mugman back home. Lots of consoling was needed, and about 4 cups of hot cocoa. Mugman exhausted himself to sleep from all of the crying, screaming, and emotional damage of having his day ruined.