It creeps through after six (5)
I believe the answer is:
'it creeps' is the definition.
The definition suggests a singular noun which matches the answer.
'through after six' is the wordplay.
'through' becomes 'per' (I've seen this before).
'after' says to put letters next to each other.
'six' becomes 'VI' (Roman numerals).
'per' put after 'vi' is 'VIPER'.
Can you help me to learn more?
(Other definitions for viper that I've seen before include "spiteful person" , "A poisonous snake or treacherous person" , "Malicious type" , "Venomous snake, person" , "Adder" .)