Archie Comics attempted to obtain a licence from Nintendo to make Kirby comics, but failed to do so.
Sword Kirby bears a strong resemblance to Link from The Legend of Zelda series, and like Link, can shoot sword beams at full health. Despite minor differences in the hat and sword designs, this is clearly an intentional reference, both Kirby and Link being well known Nintendo characters.
The enemy Pacto bares a resemblance to Namco's mascot, Pac-Man, as both have the same yellow skin color and they both open and close their mouths in similar fashions.
A program titled "Kirby Family" (a spiritual successor of Mario Family) was planned to be released for the Game Boy Color. The game was showcased at Spaceworld 2001, but the plans to retail it outside of the event for 6,800 yen on September 10, 2001 were scrapped.
The recurring enemy Cappy resembles a modern interpretation of a Haniwa doll if his mushroom "cap" is removed.
When Meta Knight is defeated in Kirby's Adventure, his mask breaks revealing his face to be identical to Kirby's, hinting that Kirby and Meta Knight are the same species.
Whip Kirby is a possible reference to Indiana Jones, as Jones has an extensible coiled whip that can be used to grab objects. Kirby also has Jones' hat, only with a star motif.
For the Kirby: Right Back at Ya 3D Short on the 3DS, the original cast members were all brought back to reprise their roles. The only exceptions were Maddie Blaustein, who didn't return to voice Chef Kawasaki as she passed away in 2008. And Andrew Rannels, who didn't return as Nightmare due to him taking a busy career on Broadway.
The Design for Dedede's Castle from the Kirby Anime is reused in Kirby: Squeak Squad, Kirby's Epic Yarn & Kirby: Mass Attack, with Squeak Squad featuring the Monster Machine from the Anime in the throne room.
While most abilities got hats in Kirby Super Star, the Hammer ability didn't get one. The current hat seen today first appeared in the Kirby anime, with some minor tweaks.
Lololo and Lalala, two recurring bosses, are actually Lolo and Lala from Eggerland/Adventures of Lolo. Both Kirby and Eggerland were developed by HAL LABS.
When Donkey Kong became popular, Nintendo was sued by Universal. Universal claimed Donkey Kong was a rip-off of King Kong. Lawyer John Kirby proved that Universal didn't even have trademark rights to "King Kong", and so they lost the case. Nintendo gave Kirby a boat named Donkey Kong and exclusive rights to the name Donkey Kong for sail-boats as a strange way of thanking him. It's also rumored the character Kirby was named after John Kirby, but this was never confirmed by Nintendo.