Animal like this in rubbish container (5)
I believe the answer is:
bison
'animal' is the definition.
(thesaurus)
'like this in rubbish container' is the wordplay.
'like this' becomes 'so'.
'in' means one lot of letters goes inside another.
'rubbish container' becomes 'bin' (I've seen this before).
'so' going into 'bin' is 'BISON'.
(Other definitions for bison that I've seen before include "Ox-like ruminant" , "European beast" , "Wild cow" , "Large humped bovid of N America" , "Big beast" .)