The I were a species working under one mind.
The I were centaurid, carapaced, covered in glass-like light-blue plating and had compound eyes. They had six fingers on each hand. They were a compound mind and referred to themselves as I. (PROSE: Seeing I)
The I were unable to develop their own ideas. Instead, they stole technology from other species, planted it like seeds amongst other civilisations and returned later to harvest the results. Galspar, Hirath, Tractis, and Ha'olam were all planets that the I conducted experiments on. (PROSE: Seeing I)
The I once intercepted Savar's escape pod, taking all relevant technology. However as Time Lord technology utilised retinal technology they also extracted his eyes. (PROSE: The Infinity Doctors, PROSE: Seeing I)