Lobri

The Lobri were creatures were created by humanity's unconsciousness and fed on humanity's fear and hatred. They existed in another dimension; a plane of existence where humanity's collective unconsciousness resided. From at least 1932 to 2082 they were clients of the Threshold who were hired to find a way out of the dimension they inhabited to allow them to manifest themselves in same dimension that humanity physically inhabited. (COMIC: Ground Zero)

Escape
The Threshold attempted to use regular human beings, transferring them to the plane on which the Lobri existed to allow them to feed on raw human fear, to prepare them for the transition to normal reality. But the regular humans were unable to cope with the transference. So instead they selected companions of the Doctor who had experience with inter-dimensional travel. (COMIC: Ground Zero)

From 1938 Peri Brown was taken, from 2082 Ace was taken and from 2086 Sarah Jane Smith was taken. Susan Foreman was also taken from 1963 the Threshold mistaking her for human. (COMIC: The Curse of the Scarab, Black Destiny, Operation Proteus, Ground Zero) Peri Brown, Sarah Jane Smith and Ace were transferred to the Lobri's plane to sustain them in preparation for their transition to the normal plane of existence. During their 'feeding' process, Ace was able to destroy most of the Lobri using Nitro-9 seemingly fatally injuring herself in the process. However the one of the Lobri was able to escape to Earth. They were prevented from feeding and distrupting humanity's collective unconsciousness by the Seventh Doctor who disabled His TARDIS' safety interlocks allowing him to materialise within the Lobri, killing it. (COMIC: Ground Zero)