At sea warn prince, finding toothed marine mammal (7)
I believe the answer is:
narwhal
'marine mammal' is the definition.
(I've seen this before)
'at sea warn prince' is the wordplay.
'at sea' indicates anagramming the letters.
'prince' becomes 'hal' (Shakespearean nickname of Henry V when a prince).
'warn' with letters rearranged gives 'narw'.
'narw'+'hal'='NARWHAL'
'finding toothed' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for narwhal that I've seen before include "Warn Hal there's a whale here" , "Tusked sea mammal" , "Sea creature with a long spiral tusk" , "Cetacean with large tusk" , "swimmer" .)