Apparently reptilian, the Bandrils lived on Banderel, a planet near Karfel.
History
The Bandrils' relationship with the Karfelons was sometimes friendly though occasionally there were moments of tension between the two neighboring races. The Bandrils subsisted in part on grain from Karfel. (TV: Timelash)
When the Dominators attacked Karfel, the Bandrils opted to remain neutral in the conflict. (PROSE: Time and Again)
The Seventh Doctor recalled once fighting the Bandrils on Waterloo Bridge with "that chap from the Kinks". (AUDIO: The Quantum Possibility Engine) Ace, a former companion of the Seventh Doctor, recalled that the TARDIS was attacked by a Bandril timeship. (AUDIO: In Remembrance)
Sometime before 1969, the Bandrils were conquered by the Dominators, although that may have been part of the usual propaganda the Dominators spread on how they were in control of the Ten Galaxies. (PROSE: Mutually Assured Domination) In late October 1969, Colonel Douglas of the Fifth Operational Corps led a platoon to deal with Bandrils in the highlands of Argyll. (PROSE: The Lost Skin)
Jo Grant recalled facing "the Bandril Armada" during her time with the Third Doctor. (AUDIO: Still Life)
The Bandrils tried to invade Earth before 1997. UNIT fought them off without the Doctor's assistance. (PROSE: The Dying Days)
In 2018, (PROSE: Lucy Wilson and the Bledoe Cadets) the Bandrils attempted to influence the minds of children so that they would kill their parents, aiding in their takeover of the Earth. To do this they created The Billy Bandril Show, which they used to influence human minds into buying the Billy Bandril toy. Lucy Wilson and Hobo Kostinen uncovered this plan, and altered the Bandril's broadcast so that the children of Earth destroyed their Billy Bandril toys, ending the invasion. (PROSE: The Bandril Invasion)
Maria and Alan Jackson were unable to attend Sarah Jane Smith's funeral in person because they missed their plane chasing a Bandril through Seattle. (WC: Farewell, Sarah Jane)
The Eighth Doctor and Charley Pollard once visited a Bandril spaceship. (AUDIO: Time Works)
Bernice Summerfield learned of a potential dig site on Javarda from a Bandril trader on Jovellia. (WC: Dead and Buried, AUDIO: Resurrecting the Past)
Bandrils once damaged the Dynormorphic generators in the Doctor's TARDIS. (PROSE: The Quantum Archangel)
Bandrils attended Garundel's auction for weaponry. (AUDIO: Starlight Robbery)
A Bandril named Calarch attended the Enormous Storage Co. auction. (COMIC: Space Invaders!)
Other references
The Eighth Doctor told Fitz Kreiner that he remembered the difference between the Bandrils and the Mandrels using the phrase, "Bad Mandrels, Mad Bandrils." (PROSE: Interference - Book One)
The Bandrils were on the Eleventh Doctor's top five enemies list which he mentioned to the Fourth Doctor and Romana II while they were making up "top five" lists. (AUDIO: Babblesphere)
Behind the scenes
Lance Parkin has stated that the Bandril invasion reference in The Dying Days was a joke, based on the Bandrils being "rubbish" monsters, and that "some alien invasions were beneath the Doctor's dignity to deal with".[1]
