Voiced by actress Nancy Cartwright, Rufus is a pet naked mole-rat owned by Ron Stoppable – Kim Possible's best friend and sidekick – and first appears in the show's pilot episode "Crush", which premiered on June 7, 2002.

Residing and traveling in his owner's pocket, Rufus accompanies Kim and Ron on missions to protect the world from evildoers, at times proving beneficial to their success.

After considering having the character portrayed by either a live or puppeted mole-rat in the live-action film, the filmmakers opted to make Rufus CG-animated instead, spending several months finalizing a design that was realistic yet appealing.

[6] However, Rufus has proven both intelligent and capable for a mole-rat, helping his teammates whenever possible and proving adept at overcoming electronic and mechanical obstacles;[3] he typically emerges from Ron's pocket to either offer assistance or eat food.

[9] Writers Bob Schooley and Mark McCorkle conceived Kim Possible as an animated television series about a teenage girl who can seemingly do anything, and her best friend who struggles to do the same, into which Rufus was incorporated once the show's "basic foundation" was written.

[16] Deciding the show's resident pet should be as unique as possible, Schooley was inspired by his children's fascination with the naked mole-rat exhibit at the Philadelphia Zoo, describing the animals as "ugly, gross, but somehow still cute creatures".

[12] Cartwright researched naked mole-rats in preparation for the role, discovering that they "are tunnel dwellers and social animals who live in large communities" who also "don’t do well out in the sunlight".

[12] Cartwright also found them to be “kind of disgusting looking", likening them to "overcooked hot dogs.”[12] The actress typically improvised and performed the role without a written script, borrowing direction from the character's emotions during particular scenes that vary from excited to sad.

[20][21] Cartwright reprised her voice role in the show's 2019 live-action film adaptation,[22][23] having hoped Disney would invite her back once the project was announced.

[12] Cartwright considers Rufus the film's only truly animated aspect,[2][24] hoping that the character's inclusion "adds this little extra thing that inspires kids.

[14] When the live-action adaptation of Kim Possible was first green-lit, the directors had considered having a live mole-rat portray Rufus, but Schooley and McCorkle determined that this would not benefit the creature itself or viewers, opting for the character to be CG-animated instead.

[29] 15 years prior, the original series had aired an episode jokingly entitled "And the Mole Rat Will Be CGI" revolving around Hollywood filmmakers and actors producing a film based on Kim's life.

"[29] Because the character needed to be more realistic than his cuter, stylized traditionally animated counterpart, the Pixomondo artists worked for several months to determine a suitable "balance between cute and real".

[27] While Blair Marnell of Nerdist opined that producers should be open to recasting the film's main characters in favor of more diverse actors, she insisted that "As long as Nancy Cartwright wants to reprise her role as the voice of Rufus, she should be able to do that for life.