It seems Gary Gygax wasn't the only game designer to give a tip of the hat to Jack's work.

There's a fantasy gaming system called Dragon Warriors that was published in six mass-market paperbacks around 1985. Volume three, The Elven Crystals, includes an adventure module called The Castle Of Terror, in which players may enlist the help of a mercenary called Mazirian.

"Mazirian is a tough fighter-mystic who will not flinch from doing his fair share of spellcasting or combat. However he will insist on a large share of any treasure discovered by the party, demanding a quarter of everything, no matter how many other characters there are in the party. He will fight to defend his right to this share and may therefore turn out to be more of a burden than an asset."
- Dragon Warriors Book Three: The Elven Crystals, by Oliver Johnson (probably with Dave Morris), ISBN 978-0-552-52289-2. Page 92.

I did a quick search on Amazon and it seems the Dragon Warriors system enjoyed a fan revival recently, with reprints and new books published (by non-original authors). Not before time, if you ask me: the originals are a childhood treasure, absorbingly written and beautifully illustrated. Wankhers may invest the sum of £0.38 to see if I'm right: