Sidekicks are a tried and true archetype in the fictional world. They don't always stand out, nor are they all that noticeable at times, but they all serve the same function. They may perform that function in different ways, but they are all there to make their partner more relatable to the audience. They do it through humor most of the time, but they can also act as storytellers and interpreters for their partners. In other ways, and when they are utilized at their weakest level, they are simply there as a prop, something for their stronger counterpart to play off of. That is the worst kind of sidekick, and one that a reader/viewer will never pay attention to, which is a waste of potential. It robs the character of being memorable, and it robs the audience of a character they could care about.
On character that hovers around the line between being a great sidekick, and an almost overlooked one, is Bookworm from a few Merry Melodies cartoons. He is the occasional sidekick for Sniffles, another character I absolutely adore, and though he never utters a word, he's frickin adorable. We first meet him in Sniffles and the Bookworm from 1939, as they wind their way through various adventures in a closed bookshop, as book characters come to live. Where Sniffles is a talkative little guy, Bookworm uses facial expressions and hand gestures, pantomime, to get his point across. He is expressive and charming, and I wanted nothing more to hang out with the two of them as a kid.
Sadly, he was only used a handful of times, but he was the right anchor for Sniffles. He would be scared, if Sniffles needed to be brave. He would be cautious, if Sniffles needed to think things through a bit more. Whatever Sniffles needed to be, Bookworm was the right catalyst for him. Between the two of them, Bookworm is probably the one who sticks in the minds of most people, at least those reading this blog, because he was probably the more relatable to our lives. He was a quite sort of guy, happier when he could bury his head in a book to read adventures, rather than living them himself. At the same time, he was a true friend for Sniffles, never letting him face the world alone, ready to face his fears, if that's what was asked of him.