This vintage, copyright free image of the letter H would make a great drop cap H. It was included in the 1885 book Unterm Birnbaum which contained a number of illustrations here on Reusable Art. It was published by Sephan Geibel and Co.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.