Inhale is King Dedede's neutral B attack. The attack is identical to Kirby's inhale, but without the copying ability. By pressing B DeDeDe will begin to inhale the air in front of him, creating a vortex. He will continue to inhale as long as B is held down. If a character comes near him, they will automatically be sucked inside of him, and will be trapped in his stomach. When swallowed, DeDeDe's stomach enlarges to hold the victim, which makes him extremely slow. DeDeDe simply spits the character back out when A is pressed, or they break free themselves.
King DeDeDe can swallow and eat Waddle Dee's he tossed using Waddle Dee Toss.
Actual gameplay footage shows that King Dedede can walk around with his victims in himself, and can perform "Dededecide" (also known as Regicide).
Much like Wario's Chomp, Dedede is able to swallow items using this attack.
Origin
In the Kirby games, Dedede has exhibited the ability to inhale foes or objects just like Kirby can. He can't, however, copy the inhaled person's abilities. For some reason, King Dedede was incapable (or simply never shown doing it) of "inhalating" in the Kirby: Right Back At Ya! anime (known as Kirby of the Stars in Japan).