10 Doctor Who Revival Era Monsters And Villains That Deserve To Return
9. Harmony Shoals
Capaldi era Doctor Who seems to have been very good at starting storylines only to leave them languishing. The last appearance of this mind controlling alien was in the superhero spoof The Return of Doctor Mysterio, where the aliens try to take over the minds of earths world leaders.
They are defeated by the Doctor, but one seemingly escapes to infiltrate UNIT.
UNIT has been absent in the recent series of Doctor Who, having apparently been shut down, and perhaps that is where things can pick back up with this particular monster. After years of internal conflict and power grabs, UNIT returns but is a lot more sinister.
Maybe some old faces return, a Lethbridge-Stewart perhaps, only to be revealed as taken over by the aliens.
They were quite a visually striking enemy, and were featured in some great episodes, but never as the main draw of that particular story. Giving them another chance to shine might yield some great results, especially in a corrupted UNIT scenario.