wolf-4
Explanation
This comic depicts the fable of "The Boy Who Cried Wolf." A boy is shouting "Wolf! Wooolf!" while an older man scolds him: "You keep yelling like that, and one day nobody will believe you when you have real trouble!"
The caption below delivers the punchline: "Fortunately, wolves were later hunted to extinction throughout the British Isles."
The traditional moral of Aesop's fable "The Boy Who Cried Wolf" is that liars will not be believed even when they tell the truth -- the boy falsely cries wolf so many times that when a real wolf appears, nobody comes to help. The comic subverts this moral entirely by pointing out a historical fact: wolves were indeed hunted to extinction in the British Isles (the last wolf in England was killed around the 15th century, in Scotland around the 18th century, and in Ireland around the late 18th century).
The joke is that the boy's lying turns out to be completely inconsequential because the entire wolf "problem" was solved independently through human predator eradication. The fable's moral about honesty and trust becomes irrelevant when the underlying threat is simply eliminated. This is a characteristically SMBC move -- taking a well-known parable or moral lesson and undermining it by applying real-world context or logic that the original story never considered.
There is also a darker layer of humor in the cheerful use of the word "fortunately" to describe the extinction of a species, treating ecological destruction as a tidy resolution to a children's fable.