Nockrauler

The Nockrauler was a legendary monster of Prague. When an artificial intelligence removed Prague from its normal time and space, it created a Nockrauler out of ooze from the Vltava River. When Peri fell into the river, it absorbed her, but she retained enough of her own consciousness to help the Sixth Doctor defeat the Nockrauler. (PROSE: Gold and Black Ooze)