The most common and most likely answer to this crossword clue is the 8 letter word TWITCHER
I've seen this crossword clue in The Times
T
W
I
T
C
H
E
R
More clues leading to the result TWITCHER
- Bird around with cherries half gone? Who could want that?
- Jittery type with an eye for the birds?
- Brief word about weird sister, keen birdwatcher
- Check for second time in social media platform for one watching birds
- Busybody by curtain is one with binoculars
- For one looking for birdies, a bad putter?
- Time to meet sorceress with hesitation — one may be nervous
- Who might spot booby and warbler?
- Nervous type who is outdoors with binoculars?
- Hobbyist who might be looking for another hobby
Buddy explains!

The straight part
We know that "Who could want that" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case who could want that = twitcher.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 TWITCHER mean?
TWITCHER noun- Someone or something that twitches.
- An eager birdwatcher who is willing to travel long distances to see rare species. (See the Wikipedia article for origin.)