Gertie (Super Gran)

 was a companion of the Twelfth Doctor. In 1986, the Doctor dropped her off and told her he'd be back at 26 September, however didn't tell her what year. (COMIC: Super Gran).

One of Gertie's adventures took place on Mars, during its earlier stages when it had water and thriving plant life. She explained to her grandson Charlie Baker that it was peaceful and quiet, until aomwrhing interrupted them, hoever it wasn't specified what.

Another adventure took place on an unspecified planet, where she encountered a Gestalt Creature which attempted to superheat the planet's surface and destroy all life - yet it was unspecified how they escaped that situation.

One time, the Doctor took her to the past to see a pyramid, yet they were attacked and chased by a mummy, although not much is known about what happened then.

After Gertie was dropped off, she waited 30 years before the Doctor arrived with Clara Oswald on a Time dragon. He took Gertie and Charlie on an adventure to Mars. (COMIC: Super Gran).