Janet (Everything Changes)

Janet was a Weevil caught by Torchwood Three and kept in its cells. Janet was kept as a secondary pet, next to Myfanwy, by Torchwood.

Personality and traits
Janet was aggressive and dangerous like most other Weevils. (TW: Everything Changes, Greeks Bearing Gifts) She apparently liked to eat paper. (REF: The Torchwood Archives)

Janet was named by Jack Harkness. He also considered the name Barbara, but found it unsuitable. (TW: Combat)

Biography
Janet lurked around the Royal Infirmary and killed a hospital porter, before she was captured by Torchwood and held in a cell. Jack Harkness later showed Gwen Cooper it when explaining how Weevils were alien. (TW: Everything Changes)

When Gwen was interrogating the Sex Gas that was controlling Carys Fletcher, she turned to another cell and was frightened when Janet jumped up. (TW: Day One)

When Toshiko was thinking about how her friends thoughts were like looking at a Weevil, she thought of Janet roaring in her pen. (TW: Greeks Bearing Gifts)

When a Weevil was killed by a person infected an alien tapeworm, Janet started whistling to mourn. Later, when Marianne Till, another victim of a tapeworm, was brought to the Torchwood cells, Janet was frightened of her and kept away from her cell. (TWN: Slow Decay)

When Torchwood was trying to find the Weevil Fight Club, they let Janet loose and used her telepathic senses to find others of her kind. She was abducted by the Fight Club and used as a wrestler. She faced Owen Harper and nearly mauled him to death, before she was captured by and returned to Torchwood. (TW: Combat)

When the cells went offline, Janet escaped, but was trapped in the hold along with Rhys Williams, who was being kept safe by Gwen. Janet did not kill Rhys, but Bilis Manger did, frighting Janet. (TW: End of Days)

When trying to prove to an undercover Sleeper Agent that there was such things as aliens, Jack threatened to feed her to Janet. (TW: Sleeper)

When interrogating Billy Davies, Ianto Jones brought in Janet, whose chain brought her mere inches away from him. Ianto got rid of her by using anti-Weevil spray. (TW: Reset)

When Weevils began to worship Owen Harper because he was a key for Durac to enter this world, he tested this by sticking his finger into Janet's pen; she didn't bite it off. (TW: Dead Man Walking) Even after Durac died, Janet was still distressed around Owen. When thinking about his death, Owen stood by Janet's pen, watching her cower away. (TW: A Day in the Death)

Janet was later released from her cell by Gray. She then attacked Gwen Cooper and John Hart, but was shot and wounded by Ianto Jones. She was then returned to her cell. (TW: Exit Wounds)

When interrogating Kerko, Jack Harkness threatened to feed him to Janet. (TWN: The Undertaker's Gift)

Janet was presumably killed when The Hub was destroyed during The 456 incident. (TW: Children of Earth: Day One)

Behind the scenes

 * Her name as Janet was revealed in Combat, but the rest of the team were oblivious to Jack's naming of her. He later used the name "Janet" to introduce the hidden Sleeper to her. Janet was stilled credited as Weevil, even after her name's revelation.
 * Beyond the name, there is little to indicate whether Janet was, in fact, a female Weevil, and the character was played by a male actor.