Akthel

An Ice Warrior joke known to Bernice Summerfield, and which Harma, upon hearign her retell it, stated he hadn't heard since "the Hatcheries", was "Ick hishack ock Akthel?!/Bisht… bisht… hasssthh…?", translating to "Why did the Akthel cross the road?! Perhaps… perhaps because it wanted to…?". (COMIC: Emperor of the Daleks!)

Behind the scenes

With the format of the joke, the clear implication is that Akthels are a Martian equivalent of Earth's chickens.