The most common and most likely answer to this crossword clue is the 5 letter word KRAIT
I've seen this crossword clue in The Guardian
K
R
A
I
T
More clues leading to the result KRAIT
Buddy explains!

The straight part
We know that "snake" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case snake = krait.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 KRAIT mean?
KRAIT noun- Any of several brightly-coloured, venomous snakes, of the genus Bungarus, of southeast Asia.