Wade Wilson, aka Deadpool, is as much known for his annoyingly incessant smart mouth as he is for his expert-level fighting ability, so it's fitting that in order to become as deadly as possible, the antihero had to choose between the two. In an alternate future of the Marvel Universe, Apocalypse embedded himself into the entire planet, taking the whole world under his Darwinistic control. In this grim future, Deadpool became one of Apocalypse’s Four Horsemen, and gained a disgusting power at the expense of his voice.
In Extraordinary X-Men #9 by Jeff Lemire and Humberto Ramos, the X-Men are sent to the future after a run-in with Sugar Man stemming from an investigation into the villain’s experimentation with mutant embryos. In that future, the X-Men discover that Apocalypse reigns supreme and has created a new team of Horsemen. As he usually does with his underlings, Apocalypse has given Moon Knight, the Venom symbiote, Deadpool, and Swamp Thing (later replaced by Colossus) new powers to enact his will.
Deadpool’s new powers as Apocalypse's Famine manifest through the antihero’s mouth, from which Deadpool can conjure a deadly cloud of locusts. In order to control this ability, Deadpool has his mouth sewn shut, and only breaks the stitching when he needs to unleash his disgusting yet incredibly effective new ability. Given Deadpool's established need to speak incessantly despite the situation, he would have unleashed a swarm of locusts he’d be unable to control. However, with his mouth sewn shut, Deadpool can better regulate the disgusting ability.
In Extraordinary X-Men #11, Deadpool finally cuts the stitching and unleashes the gross power on an attacking Iceman, which reveals to readers that - unlike in his much-derided X-Men Origins appearance - he could physically talk the whole time. Since the debut of this version of Deadpool two issues earlier, fans were given the impression that Deadpool had lost his voice altogether. In this issue, however, it is revealed that Deadpool can still speak, but is restrained by the stitching. It's a genuinely horrifying fate for Wade, who would constantly be taunted by the fact that while he technically could provide his usual meta comments, it would come at the cost of those he actually spoke to.
Traditionally, Apocalypse experiments on and brainwashes his servants, but Wade is also a capable assassin, so it's unclear whether he chose to serve the mutant villain or was captured. Either way, he was forced to sacrifice his ability to crack jokes and one-liners in favor of a swarm of insects that can eat his opponents to the bone, making him deadlier than ever at the cost of one of his defining attributes.
As a Horseman of Apocalypse, Deadpool was given a power unlike anything he had experienced before, though in order to control it he had to undergo some pretty terrifying body horror. In his Famine form, Deadpool finally got a superpower with serious offensive capabilities, but Wade's constant commentary on the world around him (and even the fact he's in a comic book) mean that if offered this choice in any circumstance outside the end of the world, he'd likely turn Apocalypse down in seconds.