The most common and most likely answer to this crossword clue is the 7 letter word GANESHA
I've seen this crossword clue in Independent
G
A
N
E
S
H
A
More clues leading to the result GANESHA
Buddy explains!
The straight part
We know that "God, at top only, has an elephant’s head surprisingly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case god, at top only, has an elephant’s head surprisingly = ganesha.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.