An extremely creative way to introduce the character into Doctor Who lore.

Here we have just a silly adventure with Mr. Ring-a-Ding being exactly what the character appears to be, a simple light-hearted Rubber Hose cartoon character.

This per se has a lot of potential. It serves as a great hook for us to create a bond and have a pre-established relationship with the character, so when we see the twisted version of him in 'Lux' chances are it'll be more impactful.

Also, the fact that Mr. Ring-a-Ding saves Easter in this story and his debut episode on the TV show is gonna be exactly the day before Easter is a nice touch.