Forgive the double post, but I don’t appear to have an edit button on my phone.
I am surprised the Ood haven’t cropped up yet, especially considering they’ve appeared in multiple episodes and been both friendly and antagonistic. Red eyed terrors or allies – it’s entirely up to you.
Mechanoids
The Yeti
UNIT – classic & modern.
Classic daleks
Slightly lower down the list, but still things I’d like to see –
Ogrons
War Machines
Ogri