Searching for a vital part of the ship that was lost during their crash-landing, Cosima and Big Lizard find Dunk stuck on a beach. They use science to save the day and make a new friend.
Source: CBeebies
Series 1: 51. One Whole Year
It's been one year since Cosima crash landed on Proxima, but no-one else has remembered this anniversary! Can a perfect picnic jolt their memories?
17-06-2025
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!
17-06-2025
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!
16-06-2025
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?
16-06-2025
CBeebies
Series 1: 23. Astronaut Health Check
Dad needs some training to pass his astronaut fitness test. Cosima and Big Lizard put him through his paces! When Rex gets into trouble, Dad’s hard work finally pays off.
15-06-2025
CBeebies
Series 1: 26. Happy Proximas!
When it unexpectedly snows, Cosima decides it must be Christmas! Rex disrupts her festive preparations, but it doesn't stop the family having a perfect 'Proximas'.
15-06-2025
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 ...
14-06-2025
CBeebies
Series 1: 25. Cosima In Charge
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?
14-06-2025
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?
13-06-2025
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!
13-06-2025
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.
12-06-2025
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.
10-05-2025
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 ...
01-06-2025
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 ...
14-06-2025
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!
21-05-2025
CBeebies
Series 1: 35. The Overfriendly Neighbours
When Big Lizard and Cosima get covered in nectar, they become unwilling house guests to some overfriendly beetles. Will Dunk come to their rescue?
26-05-2025
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?
05-06-2025
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?
31-05-2025
CBeebies
Series 1: 39. The Vegetable Robbery!
When all the vegetables from their garden are stolen, detectives Cosima and Big Lizard investigate all over the neighbourhood - only to return to the scene of the crime!
30-05-2025
CBeebies