Dad and Cosima both think they're the best at pranking. Their prank war quickly spirals out of control, until Big Lizard finally reveals Proxima's real pranking champion!
Source: CBeebies
Series 1: 13. When Dad Sleepwalked
Cosima and Big Lizard investigate the cause of Dad's mysterious sleepwalking in an adventure that takes them around Proxima and right back home again.
07-07-2025
CBeebies
Series 1: 22. The Sea Meteorite!
When a meteorite splashes into the sea, Dad and Cosima cause problems by claiming it in the name of science, against the wishes of the sea creatures.
07-07-2025
CBeebies
Series 1: 29. The Shiny Fruit
Cosima and Big Lizard find some fascinatingly slippery fruit, but bringing it safely back to the ship is more challenging than they imagined!
06-07-2025
CBeebies
Series 1: 32. All Out Of Marmalade
When Dad runs out of marmalade, Big Lizard shows Cosima a plant that's growing Proximan oranges. The leaves turn out to be giant bugs, who aren't happy about sharing their fruit!
06-07-2025
CBeebies
Series 1: 28. The Night Of The Slug
Big Lizard and Cosima undertake an exciting night-time mission rehoming a friendly slug that's taken residence in Cosima's bedroom!
05-07-2025
CBeebies
Series 1: 31. A Medical Emergency
Whilst playing doctors, Cosima discovers an animal with no heartbeat! Can Cosima and Big Lizard save the poor creature with Dad's medical kit?
05-07-2025
CBeebies
Series 1: 12. All About Home
Cosima is so excited to tell Big Lizard about her life on earth that she doesn't realise he has something exciting to say to her.
04-07-2025
CBeebies
Series 1: 21. The Problem Plant
Big Lizard frustrates Dad by stealing a strange plant from the ship. A disaster is averted when Big Lizard persuades Dad that there's more to this plant than meets the eye - and ...
04-07-2025
CBeebies
Series 1: 11. Happy Campers
Cosima and Big Lizard have a camping sleepover with a friendly little crab. In the morning, their new friend is missing, but why?
03-07-2025
CBeebies
Series 1: 20. Magnetite
A strange find far away from the ship breaks D.O.R.I.S.’s satnav. Luckily, Big Lizard’s on hand to teach Cosima how to find her way around without technology.
03-07-2025
CBeebies
Series 1: 12. All About Home
Cosima is so excited to tell Big Lizard about her life on earth that she doesn't realise he has something exciting to say to her.
04-07-2025
CBeebies
Series 1: 48. How To Speak Lizard
When Dad's Lizard Translator malfunctions, Cosima is carried away by a giant beetle! Cosima and Big Lizard realise they don't need to speak the same language to be best friends.
14-06-2025
CBeebies
Series 1: 45. Prank Day!
Dad and Cosima both think they're the best at pranking. Their prank war quickly spirals out of control, until Big Lizard finally reveals Proxima's real pranking champion!
09-06-2025
CBeebies
Series 1: 19. Best Friends Forever
Big Lizard is jealous of the vacuum cleaner and hides it from Dad and Cosima. Ammon decides it's her new best friend, whilst Cosima reassures Big Lizard that he will always be h ...
02-07-2025
CBeebies
Series 1: 21. The Problem Plant
Big Lizard frustrates Dad by stealing a strange plant from the ship. A disaster is averted when Big Lizard persuades Dad that there's more to this plant than meets the eye - and ...
04-07-2025
CBeebies
Series 1: 47. The Day We Lost Rex
Rex is missing, but Dad, Cosima and Big Lizard need him to save them from a giant slug!
11-06-2025
CBeebies
Series 1: 20. Magnetite
A strange find far away from the ship breaks D.O.R.I.S.’s satnav. Luckily, Big Lizard’s on hand to teach Cosima how to find her way around without technology.
03-07-2025
CBeebies
Series 1: 11. Happy Campers
Cosima and Big Lizard have a camping sleepover with a friendly little crab. In the morning, their new friend is missing, but why?
03-07-2025
CBeebies
Series 1: 32. All Out Of Marmalade
When Dad runs out of marmalade, Big Lizard shows Cosima a plant that's growing Proximan oranges. The leaves turn out to be giant bugs, who aren't happy about sharing their fruit!
06-07-2025
CBeebies
Series 1: 28. The Night Of The Slug
Big Lizard and Cosima undertake an exciting night-time mission rehoming a friendly slug that's taken residence in Cosima's bedroom!
05-07-2025
CBeebies