Dad has left Cosima in charge for the day. It seems like an excellent opportunity to have a massive party! What could possibly go wrong?
Source: CBeebies
Series 1: 9. How To Work Together
Cosima, Big Lizard and Ammon are squabbling over Dad's precious explorer notebook when disaster strikes. Only by working together can they save it from being lost forever!
21-04-2025
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 ...
21-04-2025
CBeebies
Series 1: 33. After The Storm
After a storm passes overhead, many creatures turn up in surprising places and need Cosima and Big Lizard's help. But try as they might, the friends can't find poor Rex.
20-04-2025
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.' ...
20-04-2025
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!
19-04-2025
CBeebies
Series 1: 8. Hot And Cold
Volcanic smoke blocks the three Proximan suns, which causes Big Lizard to become worryingly cold. Cosima's on the case and comes up with a superhot solution!
18-04-2025
CBeebies
Series 1: 18. Dad's Birthday
When Cosima wrongly accuses Big Lizard of eating Dad's birthday cake, he vanishes. Has he run away, or is he planning a special surprise to save the day?
18-04-2025
CBeebies
Series 1: 17. The Cocoon
A dragonfly steals a bee cocoon that Cosima had vowed to keep safe. Cosima and Big Lizard give chase, leading to a surprising solution with a vacuum cleaner and some sticky vines!
17-04-2025
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!
16-04-2025
CBeebies
Series 1: 16. Crystals!
Big Lizard has found an epic crystal, and Cosima is jealous. Their squabbling reaches its peak at the top of the volcano! Will they learn to share before it's too late?
16-04-2025
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 ...
21-04-2025
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!
19-04-2025
CBeebies
Series 1: 27. The Day Ammon Overcame Her Fear
Ammon gets spooked by a tiny insect, but overcomes her fear to rescue Cosima and Big Lizard from the rapids.
30-03-2025
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?
08-04-2025
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.
02-04-2025
CBeebies
Series 1: 9. How To Work Together
Cosima, Big Lizard and Ammon are squabbling over Dad's precious explorer notebook when disaster strikes. Only by working together can they save it from being lost forever!
21-04-2025
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!
27-03-2025
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.
09-04-2025
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.
10-04-2025
CBeebies
Series 1: 38. All About Coral
Big Lizard and Cosima create a fantastic water ride when they dislodge an underwater rock blocking a volcanic vent. It's all good fun until they realise the sea is starting to c ...
19-03-2025
CBeebies