"a small slimy creature" was added after this picture was drawn, in the 1966 edition.

Other languages adaptions had larger gollum's also - see some at e.g. https://www.reddit.com/r/lotr/comments/vy7vij/before_the_196...

(It's difficult to find an excellent authoritative link clearly explaining that the change was in the 1966 edition - there is 'The History of The Hobbit' by John D. Rateliff, but I can't find it online)