Basic Trope: A moral lesson is established by showing improbably serious consequences of doing something wrong.
Straight: Spencer throws some used toys on the ground instead of disposing of them properly. It kills off some vegetation and makes some of the flowers mutate into something ugly. Spencer has to pay a hefty fine and deal with angry people who loved the vegetation.
Exaggerated: Spencer throws a single candy wrapper on the ground. He is kidnapped by a witch who turns him into a flower and poisons him, explaining that "now you'll know how the plants feel when people litter".
Spencer (friendlily) teases William. The latter becomes a bullying victim because others imitate and exaggerate Spencer's behaviour, failing to understand that Spencer was just joking.
Spencer throws a Banana Peel on the ground. William slips on it and falls. He suffers some minor injuries that aren't probable for a young boy that falls, but can happen nonetheless.
Justified: It turns out that the toys contained dangerous chemicals that are potentially fatal for plants, and the batteries leak easily.