Wallscrawl

"Wallscrawl" was the name given to the Kang drawings on the walls of Paradise Towers. They depicted various objects and themes such as the cleaners. One of the tasks the Caretakers were responsible for was removing wallscrawls. This led them to nickname the Kangs "wallscrawlers".

After Pex's apparent death sacrificing himself to kill Kroagnon, a wallscrawl visible when the Doctor's TARDIS dematerialised stated "Pex lives". (DW: Paradise Towers)