The most common and most likely answer to this crossword clue is the 14 letter word HIPPOPOTAMUSES
I've seen this crossword clue in The Sunday Telegraph
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More clues leading to the result HIPPOPOTAMUSES
- Fruit taken by river vessel diverts animals
- With trendy music and books, entertains large African natives
- After fruit drink, book entertains those who like to wallow
- They wallow in shoot-’em-up apps, I suspect
- More than one wild animal in river by vessel delights
- Fashionable river vessel makes diversion for semiaquatic creatures
- Funky river vessel tickles giants of the Zambezi, say?
- Cool dad books delights for large short-legged creatures
Buddy explains!

The straight part
We know that "semiaquatic creatures" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case semiaquatic creatures = hippopotamuses.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HIPPOPOTAMUSES mean?
HIPPOPOTAMUSES noun- A large, semi-aquatic, herbivorous (plant-eating) African mammal (Hippopotamus amphibius)