For those who caught my previous linking to Lumia's Kingdom where I complimented the comic on it's restraint for the matters it made jokes of, the latest update threw the restraint to the floor.
Now, since I know there is a possibility that artist might read this on his own, here's how I would have handled the comic for greater comedic effect.
I would have had Leon shut the door after the line: You killed over 1,000 people, including your own MOTHER!
From the opposite side have the more generic cuss word symbols filtering through the door, indicating the plant is screaming, with some words like EATON BY CARRION BIRDS filtering through. Then use Leon to comment that the plant still hadn't gotten over the Von Drechsler spell.
Comic readers then get the idea that the plant is foul-mouthed, nothing is actually spelled out, and the Von Drechsler name is placed into the story for future consideration.
At the same time, the joke is delivered that the plant is so powerless, it can't stop Leon from shutting the door on it, thereby contributing to the humiliating factor. Leon won't even stay in earshot to get the full rant.