The Krillitanes were a race that could take physical features from races they conquered. They appear as the main villains in the Doctor Who episode called "School Reunion".
Ten generations before 2007, the Krillitane conquered Bessan, killing millions. They took bat-like wings from the inhabitants (TV: School Reunion).
In 1140, Lozla Nataniel Henk attempted to breed Krillitanes in Worcester, but was defeated by the Tenth Doctor. By using their own oil against them, Henk attempted to create a huge, mutated Super Krillitane that he could sell to the highest bidder as a weapon. However, the creature was killed when Captain Darke threw a vial of Krillitane oil into its mouth as it was rampaging around the city of Worcester (PROSE: The Krillitane Storm).
They were creatures with long necks, but then they evoluted and now have bat-like wings.