• 
  Joan Rivers
• 
  Brian Blessed

   Eduardo Enormomonster (4 episodes, 2013)
• 
  Lori Alan

   Momma (21 episodes, 2013-2014)
• 
  Grey Griffin

   Nan-oh / ... (17 episodes, 2013-2014)
• 
  Sue Elliott-Nichols

  (3 episodes, 2013)
• 
  Teresa Gallagher

  (4 episodes, 2013)
• 
  Lara Jill Miller

   Henry (9 episodes, 2013)
• 
  Tom Kenny

   Daddo / ... (19 episodes, 2013-2014)

• 
  Rob Paulsen

   Denzel Dugglemonster (4 episodes, 2013)
• 
  Cree Summer

  (4 episodes, 2013)
• 
  Hynden Walch

   Summer (9 episodes, 2013)
• 
  Tim Whitnall

  (4 episodes, 2013)
• 
  Jane Whittenshaw

  (4 episodes, 2013)
• 
  Chiara Zanni

   Cobby (19 episodes, 2013-2014)
• 
  Beth Chalmers

  (4 episodes, 2013)

• 
  Kari Wahlgren

   Ivor (7 episodes, 2013)
• 
  Naomi McDonald

  (4 episodes, 2013)