Why did the patchies die?

That one on the right is her little one. Patchies are very faint of heart, and easily succumb to anti-yukkuritis.

a bit of wordplay here:
-The previous pages had the text "Rest assured, they're wearing items of clothing".
-This page: "Rest assured, she's puking"

The pun lies in that "to wear" and "to vomit" are all read as "haku".