humourous in an unusual way
droll - humourous
If a person is described as being ‘droll’ then they are considered to be amusing in an unpredictable and unconventional way. That means that it might not be a form of humour everybody gets or appreciates, but the many that do typically find it witty and appealing. Most commonly encountered in written rather than spoken English.
Richard has quite a droll sense of humour which not everybody gets, but those that do find it highly enjoyable.
That work of non-fiction was so impactful and accessible because it used droll humour to explore difficult and traumatic subjects.
The politician tends to brush off harsh criticism from the media with drollery. It is a trait many voters find to be quite endearing.