Beastly types from trendy post offices (6)
I believe the answer is:
hippos
'beastly types' is the definition.
Although both the answer and definition are plural nouns, I cannot understand how one could define the other.
'trendy post offices' is the wordplay.
'trendy' becomes 'hip' (I've seen this in other clues).
'post offices' becomes 'pos' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'hip'+'pos'='HIPPOS'
'from' is the link.
Can you help me to learn more?
(Other definitions for hippos that I've seen before include "African natives" , "River horses" .)