If 'exemplary' describes behaviour that is a good example of what to do, is there an adjective that describes behaviour that is a good example of what not to do?
He was famous for his exemplary behaviour.
He was infamous for his [ ... ] behaviour.
The comedian was outrageous. His performances were exemplary.
The comedian was boring. His performances were [ ... ].
My first guesses would be inexemplary and nonexemplary but I can't find a reference for either of these.