Octonauts (which are many I think outside the UK). It is a cartoon based on Books by Meomi (from Canada). They are very popular on CBeebies. My kids love it. Every evening they want me to make up an Octonaut story. Which is quite hard as the characters have pretty flat personalities and the storyline is usually the same.
I try to convince my spouse to make Captain Barnacles for the kids. So far no luck. I did find this little fella on the blog of Steel & Stitch: Kwazii. The oh-so-brave but not the smartest cat. He used to be a pirate or comes from a pirate family or so. At least his grandfather was a pirate.
Click here for the free crochet pattern on Steel & Stitch blog
Update: here is a link for Captain Barnacles, also from Steel & Stitch. From K and J Dolls is a pattern of another Octonaut: a Vegimal.