Hornet

The Hornets were an insect species which resembled the hornets of Earth. They came to Earth to invade.

History
The Hornets first encountered the Fourth Doctor in Tilling Abbey in 1039, although for the Doctor, this was his fourth encounter with them, as he had encountered the Hornets in reverse order. They possessed a pack of wild dogs, led by a dog the Doctor named Captain. They used the Doctor's TARDIS to travel to Venice in 1768, where they left Captain and instead possessed Antonio. (AUDIO: A Sting in the Tale)

The Hornets used Antonio to set up the Circus of Delights. With Antonio as the ringleader, and the Hornets plotted to kill the town by enlisting them in the dreadful "Circus of Delights" where... accidents happened. They would have possessed/killed the entire town had the Doctor not stopped them. However the Hornets possessed tightrope walker Francesca, and compelled her to jump off the high wire, and died. The Hornets remained dormant in Francesca's dead body, and eventually, her mummified feet and ballet shoes would make their way to the museum in Cromer. (AUDIO: The Circus of Doom

By stinging famous dancer Ernestina Stott, the Hornets were able to possess her and used Mrs Wibbsey's voice to command her to sacrifice her life to the sea. They possessed a China Doll in order to speak with the Doctor while he was inside the Victorian house. (AUDIO: The Dead Shoes)

They possessed stuffed animals and Ernestina's grandson Percy Noggins, the director of a factory. They thought the Doctor would be a good host, but he avoided this by escorting them to his home at Nest Cottage. (AUDIO: The Stuff of Nightmares)