Guest Stars Ardal O'Hanlon voices Martin Regan Shaun Mason as Randall Chris Lew Kum Hoi as Gregor Mansell Siobhán McSweeney as Mary Abraham Popoola as Ade Olivia Marcus as Megan Julian Barratt as George Kwaku Mills as Clark Mona Goodwin as Denise Clinic Receptionist Rory Murphy as Void Man Guy Lewis as Father Alex Murdoch as Cat Adopter Woman Lily King as Little Girl