To me fishhook holes have dogleg turns of 90 degrees or more, with some sort of buttress impeding progress across the dogleg.
I ran into one of these Friday at Stewart Park GC in Roseburg, OR. Lacking a camera we'll have to do with a scorecard diagram of the 6th/15th hole.
In par 5 mode it plays 435, which would require a 335 yd drive to reach the corner. As a par 4 the range is 290-340 with a drive along a flat, un-bunkered fairway. When you reach the corner of the dogleg you see the green benched into the hillside about 60-80 feet above and maybe 100 yard away, fiercely guarded by trees on the left side. One of its victims was a golf rater (hdcp) who used a wrong adjective to describe it in a newspaper article. IMO it is the strongest hole at the municipal course (1960?, architect unknown).
How common is this type of hole?