Males, I agree, can be a lot of beasts (9)
I believe the answer is:
menagerie
'beasts' is the definition.
(a menagerie is a collection of animals)
'males i agree can be' is the wordplay.
'males' becomes 'men' (man is a kind of male).
'can be' is an anagram indicator.
'i'+'agree'='iagree'
'iagree' is an anagram of 'agerie'.
'men'+'agerie'='MENAGERIE'
'a lot of' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for menagerie that I've seen before include "[TENNESSEE WILLIAMS] work in part" , "Animals go in here" , "Assembly of animals" , "Animal exhibition" , "where the occupants behave like animals" .)