Jason got Penguin sick once, way back when he was Robin.
Penguin is convinced it was intentional because:
1) HE WASN’T SICK WHEN BATMAN ROLLED IN DEMANDING INFORMATION TWENTY MINUTES AGO (kids get sick in seconds, I’m not kidding, I once went to school healthy and had pneumonia when I went home).
2) Dove didn’t get sick. Which, okay, la-dee-da, BUT Dove got a hug. Penguin was five feet away at all times. How. HOW. (Dove takes Airborne and has a decent immune system.)
Penguin being, well, Like That...is bitter about his two-week, Robin-borne illness to this day. Never mind the snide comments. Never mind the decapitations. That little shit got him SICK on PURPOSE and HE WILL PAY ONE DAY.