Beast put uranium in criminal cargo (6)
I believe the answer is:
cougar
'beast' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'uranium in criminal cargo' is the wordplay.
'uranium' becomes 'U' (U is the chemical symbol for uranium).
'in' means one lot of letters goes inside another.
'criminal' indicates an anagram.
'cargo' with letters rearranged gives 'cogar'.
'u' inserted inside 'cogar' is 'COUGAR'.
'put' is the link.
Can you help me to learn more?
(Other definitions for cougar that I've seen before include "Cat, aka puma" , "North American mountain lion" , "Big cat" , "Another name for puma" , "North American puma" .)