Alex surmised: "If was in the desert, I would need to find water."
With detailed sketches, numbers and captions, the boy's survival plan begins by digging a hole.
At step two, he moves on to cutting down a cactus with a sword. And finally he appears to suggest using the cactus as a receptacle to urinate into, which he illustrates with a drawing of a penis and the letters "PP".
Redditors seemed to be most amused by this final step.
User TheCouchPundit joked "What an odd-looking cactus - wait." And HowIsYourFather complimented the 9-year-old's drawing ability: "I have to say his drawing skill is pretty advanced for his age."
One user, MrBaoom, decided Alex must have been watching survival programmes and posts: "Bear Grylls would be proud."
Others were impressed with his water-catching concept. Smooman21 asked: "Is he trying to make an evaporation catch with his pee? Seems pretty damn clever to me."
MadroxKran disagreed: "I hear drinking pee actually makes you more dehydrated because of the salt content."
A Redditor who claimed to live in the desert offered a much more simple idea: "As someone who lives in the desert. I'd probably pick up a case of water at the store."
Since the image was posted on Tuesday it has been viewed almost 469, 000 times.
- nzherald.co.nz