Dracula is one of those stories that many people know of (and this assumption could also be made of the characters within) but don’t actually know. There have been several films of course, but as usual, they are not necessarily faithful to the original Bram Stoker (whom I have also played for German television: go to my professional acting page, and click on the Bram Stoker for German TV link in the Clips column) novel.
Inasmuch as any character could, with adequate justification, be said to be pivotal to the story, van Helsing (or Professor Doctor Abraham van Helsing MD, D.Ph, D.Litt., etc., etc., to give him his correct title) is absolutely pivotal, whereas the author of the play from this version of the story, Liz Lochhead, has altered some characters and aspects from the original. As usual (but with the requisite circumspection), the Wikipedia page for him is the best source of information outside the novel; he is described as being clean-shaven (and, by implication, short-haired, as evidenced by the photo on the Wikipedia page of Edward van Sloan, who played him in the 1931 film), but I think his personality is unconventional enough that my inescapably hirsute and long-haired appearance was not considered unacceptable! I grew a van Dyke style goatee to emphasise his Dutch background.
I think this is without doubt the most difficult amateur rôle I have ever taken on, not only because of the number of lines and the individual choice of language that he uses, but also as a result of having to be aware of accenting nearly every word in a Dutch way, while enunciating them as clearly and audibly as possible. Another consideration was having to try to retain focus for the whole of the first act, because he does not appear until the beginning of act two! On the plus side, my costume (a Harris Tweed suit) was marvellous, albeit very warm under the stage lighting! Overall, it was a most enjoyable & rewarding experience, with a brilliant cast too numerous to mention, but I am forever indebted to the Director, Ivan Hall, who also, to his immense credit, took on (albeit entirely expediently) the extremely demanding rôle of the lunatic(?) Renfield.