The most common and most likely answer to this crossword clue is the 9 letter word ELEPHANTS
I've seen this crossword clue in The Guardian
E
L
E
P
H
A
N
T
S
More clues leading to the result ELEPHANTS
- The planes flying could be jumbos
- . Those making trunk calls plan these changes
- A net helps wild animals
- Great footballer retiring, hasn’t played for Ivory Coast national team?
- Trump sources regularly tell me husband wears trousers
- They never forget footballer returning to county
- Animals long kept in pens hate going out
- The planes needing repair — jumbos
- Creatures great, creatures small, brought to earth with mysterious help
- Engineer to help ants' evolution into giant beasts
Buddy explains!

The straight part
We know that "Animals" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case animals = elephants.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 ELEPHANTS mean?
ELEPHANTS noun- A mammal of the order Proboscidea, having a trunk, and two large ivory tusks jutting from the upper jaw.
- Anything huge and ponderous.
- Used when counting to add length, so that each count takes about one second
- Ivory.
- A large size of paper, measuring 23 by 28 inches, or sometimes 22 by 30, or (double elephant paper) 26 by 40 inches.