Little wriggler wriggling in lead pot (7)
I believe the answer is:
tadpole
'little wriggler' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'wriggling in lead pot' is the wordplay.
'lead pot' can be anagrammed to 'TADPOLE'.
However, I am not clear how the anagram is indicated.
Can you help me to learn more?
(Other definitions for tadpole that I've seen before include "young swimmer" , "Embryonic frog" , "To plead for tiny frog" , "Immature amphibian" , "Pre-frog form" .)