The series is all about a family of hyenas who disguise themselves as humans.
They get up to a load of mischievous stuff, including going on holiday, and moving into a new house!
Julian and David chat about the new book in the series and how they came up with their crazy ideas.
Plus, David drew suggestions that you sent in on Popjam!
They included a lizard in a sombrero and a pig unicorn! Check that out below!