I’m looking for the title of a picture book that I read as a child in the mid-1990s. I believe the book was written in the 1980s or 90s, though it could also be from the 70s. I don’t remember any part of the title. It was a large-format hardcover edition.

It features illustrations with a watercolor style and a brightly colored, somewhat flat, surreal aesthetic with greatly exaggerated proportions. Its protagonist is an explorer who is dressed in a blue 19th-century naval outfit and sailing a large (and very tall) ship by himself.

He is searching for a rare creature that has some giraffe-like features and eats bananas, and on every page you can see that this creature is following him just out of sight. During his exploration, the protagonist meets several huge, frightening monsters, one of which I seem to recall was named the “purple lumpy thumpet”.

When the explorer finally finds his creature, it is revealed that it has many babies, and also that the monsters he encountered earlier were all friendly. All characters then have a picnic together on an island.

As a young child I read this book over and over again, captivated by its unique blend of unsettling, dreamlike  visuals and mischievous, lighthearted storytelling. I have now been searching for its title for nearly a decade with no luck, and just found out about this service.