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: 2. The Trouble With Trilobites
When a pack of pesky, migrating trilobites overrun the ship, Big Lizard has to use a hidden talent to lure them away. But one little trilobite, Rex, decides to stay.
03-09-2025
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.
03-09-2025
CBeebies
Series 1: 1. The Day We Landed
Whilst exploring deep space, a meteor strikes Cosima and Dad's ship! After crash-landing on the unexplored planet of Proxima, Cosima makes a new best friend called Big Lizard.
02-09-2025
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?
02-09-2025
CBeebies
Series 1: 52. The Day We Left
When D.O.R.I.S. reveals a large meteor is about to land on the spaceship, it's finally time to leave. But should Big Lizard leave too? What about all those who need him on Proxima?
01-09-2025
CBeebies
Series 1: 10. When We Lost D.o.r.i.s.'s Brain
When a giant beetle steals D.O.R.I.S.'s brain, thinking it's a nut, Cosima and Big Lizard give chase through the forest. Big Lizard uses unique skills to rescue poor D.O.R.I.S.' ...
01-09-2025
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!
31-08-2025
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.
31-08-2025
CBeebies
Series 1: 44. The Hoverboard Race
During a hoverboard race, Dad's new super-powered hoverboard malfunctions, so Cosima and Big Lizard throw the race to rescue him!
30-08-2025
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!
30-08-2025
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?
02-09-2025
CBeebies
Series 1: 49. A Big Day Out For D.o.r.i.s.
Dad gets trapped in the shower when D.O.R.I.S. decides to visit the sea. Can Big Lizard and Cosima stop her before she does herself permanent damage?
27-08-2025
CBeebies
Series 1: 7. How To Hoverboard
Cosima and Big Lizard's solar-powered hoverboards run out of battery at nightfall. Can glowbugs be the answer?
27-08-2025
CBeebies
Series 1: 1. The Day We Landed
Whilst exploring deep space, a meteor strikes Cosima and Dad's ship! After crash-landing on the unexplored planet of Proxima, Cosima makes a new best friend called Big Lizard.
02-09-2025
CBeebies
Series 1: 6. The Missing Volleyball
Twig steals Cosima's volleyball. A chase leads Big Lizard and Cosima to her den... and also to a happy discovery!
26-08-2025
CBeebies
Series 1: 10. When We Lost D.o.r.i.s.'s Brain
When a giant beetle steals D.O.R.I.S.'s brain, thinking it's a nut, Cosima and Big Lizard give chase through the forest. Big Lizard uses unique skills to rescue poor D.O.R.I.S.' ...
01-09-2025
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.
31-08-2025
CBeebies
Series 1: 50. The Earth Probe
Finding an earth probe makes Dad homesick. When Big Lizard accidentally destroys it, Cosima knows what to do. She recreates the contents - Proxima-style!
28-08-2025
CBeebies
Series 1: 44. The Hoverboard Race
During a hoverboard race, Dad's new super-powered hoverboard malfunctions, so Cosima and Big Lizard throw the race to rescue him!
30-08-2025
CBeebies
Series 1: 2. The Trouble With Trilobites
When a pack of pesky, migrating trilobites overrun the ship, Big Lizard has to use a hidden talent to lure them away. But one little trilobite, Rex, decides to stay.
03-09-2025
CBeebies