A Tree
Explanation
The Joke
A man on his deathbed describes his elaborate posthumous revenge plan: he wants a tree planted above his body, and over his lifetime he has filled his body with heavy metals like cadmium and lead. When the tree's roots reach his corpse, it will suck up those toxic metals, and children will gather around to eat the tree's fruit -- thus being poisoned. He laughs maniacally at this plan ("Hahahaha!"). The hospital staff, visibly disturbed, decide they are going to have him cremated instead. In the final panel, the dying man pivots: "Please spread my ashes in the air-recirculator of a plane" -- revealing that no matter the disposal method, he has a contingency plan to harm people after death.
The Humor
The comic is a dark comedy about a cartoonishly villainous dying man whose sole concern is posthumous harm. The escalation is key: the initial plan involving a poison tree is already absurd and overly elaborate, like a Bond villain's scheme. When the staff tries to thwart him with cremation, his immediate pivot to asking for his toxic ashes to be spread through an airplane's ventilation system shows he has thought through every contingency. The humor lies in the sheer commitment to villainy even on one's deathbed, and the staff's growing horror at realizing there may be no safe way to dispose of this person. It parodies the sentimental tradition of memorial trees and ash-scattering, turning each into a vehicle for cartoonish evil.