Zama fly

A zama fly was an apparently non-sentient insectoid species native to the planet of the Ukrakks. They were, however, massive in comparison to Earth flies. A normally-sized adult humanoid was smaller than one of a zama fly's legs.

As Professor Lammers noted to the Third Doctor, they were an enemy of the Ugrakks. Because the Ugrakks held dominion over the flora of their planet, they were able to use equally huge flowers to fire deadly spores against zama flies who approached the Ugrakk city.

Lammers and the Doctor once hitched a ride on a zama fly, but had to bail once the Ugrakk spore attack became too intense. (TVA: The Ugrakks)