Tumour alien
From Tardis Wiki, the free Doctor Who reference
The Tuma alien was a grey blob that attatched itself to victim's brains and killed them. If it is disturbed, then it released a toxic gas. One passed through the Cardiff rift and attached itself to Katie Russell. When she was operated on, it killed all of the surgeons, along with Katie. Jack Harkness presumably got rid of it. (TW: Fragments)
| ||||||||||||||||||||||||||||||||||||||
