A group of undesirables regularly goes wild (6,7)
I believe the answer is:
rogues gallery
'a group of undesirables' is the definition.
(I've seen this before)
'regularly goes wild' is the wordplay.
'wild' is an anagram indicator.
'regularly'+'goes'='regularlygoes'
'regularlygoes' anagrammed gives 'ROGUES' GALLERY'.
(Other definitions for rogues gallery that I've seen before include "Police collection of photos of known criminals" , "Collection of pictures of criminals" , "Mug collection" , "Group of undesirables" , "Group of disreputable people" .)