Lizard

Lizards were a type of reptile with tympanic membranes close to the skin. (COMIC: Ripper's Curse)

The name "Dinosaur" etymologically meant "Terrible lizard"; the Fourth Doctor once told his companion that this was something of a misnomer, as Dinosaurs were reptiles, but not, technically, lizards. (PROSE: The Doctor Who Dinosaur Book)

In the 1970s, Professor Tansbury's experiment resulted in the creation of a giant lizard. (COMIC: The Tansbury Experiment)

In the 2010s, Bill Potts saw a film on Netflix about lizards in people's brains, controlling them. She related this to what she was seeing with Heather, and the Twelfth Doctor ridiculed Bill for coming to this conclusion first, of all things. (TV: The Pilot)

On Uxarieus in 2472, the IMC tried to drive off the the colonists living there by using a robot and projections to make it appear that giant lizards were attacking. (TV: Colony in Space)

The First Doctor, John and Gillian visited a planet inhabited by giant lizards which briefly captured them. (COMIC: Lizardworld)

The Seventh Doctor briefly turned Chris Cwej into a lizard. (PROSE: Sky Pirates!)

While scanning space for Cyber-Warships, the Seventh Doctor spotted a lizard coming out from hiding and realised the ships were camouflaged. (TV: Silver Nemesis)

Chromatic lizards were a species native to Rokhandi. (COMIC: The Friendly Place)

Lizardkind lived on New Earth. (AUDIO: The Cats of New Cairo)

A species of giant lizards existed on Gallifrey in its prehistory. The beasts were Time Scooped to the present day during the Last Great Time War as part of the Time Lords' war effort and took up residence in the Death Zone. PROSE: Engines of War) A Time Lord pondered if the creatures might still live by the time that Gallifrey returned to N-Space. (PROSE: A Brief History of Time Lords)