Dennis the Menace and Gnasher, originally known as Dennis the Menace, is a long-running children's comic strip series printed in The Beano. As with the majority of series published in the magazine, it is set in the magazine-wide setting of Beanotown. The series has gained several adaptations onto television, such as the BBC series Dennis and Gnasher, as well as some spinoff book series.
The series principally stars the titular main characters of Dennis the Menace and his dog Gnasher. Other characters include Dennis' baby sister Bea, Dennis' gran, and some commonly-antagonistic characters, Walter Brown, Walter's friend Bertie Blenkinsop, and Sergeant Slipper.
Crossovers[]
The series has several crossovers with the Doctor Who universe across various publications and networks.
The earliest of these crossovers occurred in the 60-page comic story The Totally Stonking, Surprisingly Educational And Utterly Mindboggling Comic Relief Comic [+]Dan Abnett, et al., Fleetway Publications (1991)., where Dennis and Gnasher appeared as participants in Red Nose Day 1991, while several incarnations of the Doctor, their companions, and the TARDIS appeared elsewhere in the comic.
Next, the BBC Children in Need charity special Future Generations [+]Children in Need (BBC1, 1998). featured Dennis and Gnasher on Festive Road (from Mr Benn) and, later in the same scene, a pair of Daleks appear.

Dennis calls Gnasher in to clean, among others, a Dalek. (COMIC: Dennis the Menace in Balloonatics [+]BeanoMAX comic stories (DC Thomson, 2007).)
Following this, the first issue of BeanoMAX was released as a Comic Relief special, officially crossing the DWU over with several strips published in The Beano. Dennis and Gnasher appeared in the two-part comic Dennis the Menace in Balloonatics [+]BeanoMAX comic stories (DC Thomson, 2007)., which involved Gnasher licking jam off of a Dalek, and Walter recognising the Dalek, among others, as a celebrity. The comic Dennis meets Jonathan Ross [+]BeanoMAX comic stories (DC Thomson, 2007). featured a team-up between Dennis the Menace and Jonathan Ross, as well as featuring a reference to the Dalek Ross encountered at Bash Street School in The Invasion of Bash Street [+]Alan Digby, BeanoMAX comic stories (DC Thomson, 2007)..
References to Dennis the Menace and Gnasher in the Doctor Who universe[]

The front and back covers of The Beano Summer Special 1981. (TV: The Rings of Akhaten [+]Neil Cross, Doctor Who series 7 (BBC One, 2013).)
Joe Sterling is said to have worn a Dennis jumper at least once in the Torchwood novel Almost Perfect [+]James Goss, BBC Torchwood novels (BBC Books, 2008)..
Dennis and Gnasher can be seen on the front and back covers of The Beano Summer Special 1981 in The Rings of Akhaten [+]Neil Cross, Doctor Who series 7 (BBC One, 2013). and The Universe is Calling [+]Doctor Who Series 11 teaser (BBC One, 2018)., while Walter Brown, Bertie Blenkinsop, and Spotty Perkins visible on the back cover.
References to the Doctor Who universe in Dennis the Menace and Gnasher[]

The cover of The Beano #3651.
Some appearances by Dennis the Menace and Gnasher characters in other Beano strips have occurred alongside references to the Doctor Who universe.
The cover art of The Beano #3651 depicts Walter Brown inside a Dalek casing, with Gnasher preparing to urinate on him and Dennis threatening to splat him with his sonic catapult.
Dennis the Menace and Gnasher were featured on the cover art of The Beano #3695, an anniversary issue, which depicted a single scene also involving a Dalek.

A Dalek-like post box climbs up the stairs towards Dennis. (Bananaman)
He was later among the Beano characters who made an appearance in the Bananaman strip published in The Beano #3869, which had various characters be arrested by Dalek-like post boxes. He was one of the main characters in the narrative, with Dennis directly referencing the common joke that they couldn't climb stairs, only for one to immediately climb after him.
Other connections[]
To be added