Finnish is nice for this as well. The grammar is mostly about inflected forms so you can keep things together in a single word, you can most often find a way to

Finnish is nice for this as well. The grammar is mostly about inflected forms so you can keep things together in a single word, you can most often find a way to write words together, and even creating completely new yet understandable words by joining existing words together or applying onomatopoetics is doable.