I am told this meme is two years old and Smaug has since slipped down to #19.
It seems Forbes gave up on ranking fictional characters’ wealth after 2013, before things got quite so extremely unbalanced, so I don’t know what the situation now would be but yes, in 2013 Scrooge McDuck was at the top of the heap with an estimated $65.4 billion, which an online inflation calculator suggests would be worth about $83.3 billion today. The current richest human (January 2023), Bernard Arnault, has $190 billion.