According to Wikipedia:
Crusties is a term for members of a subculture. The term pre-dates crust punk and can be used independently to refer to street punks or squatters.  The trend was most widespread in the UK in the late 1980s and early 1990s but there are also international subsets. Members are noted for their unkempt appearance and are associated with raves, road protests, beggars, squatters, street entertainers and the young homeless.
Typical dress styles involve dirty unkempt clothing, body piercing, matted messy hair (dreads) and sub-decent hygiene. Crusties are seen as being typically young, homeless and unemployed. This association is such that the term crusty can often be because of their matted, dirty style of dress.
The term ‘crusties’ is also used in the related field of body piercing for the dried, crusty leakage from a new piercing.
The term may now be more notable for its associations to Crust Punk.
I think they are rattle-rattle and yucky. The Mister said I was showing my age. If taking a bath and doing more than hanging with your dog is showing my age, then hand me a cane.
Only in America.
Shaking My Got Dang Head Hard