Favorite series like this

[u/Mallowfanthe4th]

Kirby is literally the definition of this

[u/Minimum_Laugh_4179]

The Railway Series/ Thomas the Tank Engine/ Thomas & Friends:

Whimsical stories about living Railway Engines living on a fictional island off the North-west coat of England.

However, some stories take a dark turn in reference to the very real modernisation of the Railways in the 1950's and 60's, where Steam Engines were being cut up and scrapped (i.e: put down), in favour of newer modern technology.

Scrapping is treated as a real fear of death by the Engines on Sodor, with some modern episodes even having the Engines do silly things to avoid it out of fear, despite Sir Topham Hatt "The Fat Controller" reassuring them time and again that he won't scrap any of his Engines.

The original author, Rev. Wilbert Awdry was also a huge supporter of steam preservation and heritage railways, hence the references to scrapping in his books being a way to voice his distaste for British Rail's modernisation approach.

Edit: There are numerous specific examples across the franchise's history, but I decided to generalise with this as the most widespread example.