Fafhrd and the Mouser fight pirates. Uncredited inking assistance, possibly by Berni Wrightson (page 1); Mike Kaluta (pages 11 and 12); Walt Simonson (page 23); and other such as Sal Amendola and Vincente Alcazar, and others. Information per Nick Caputo, Jan 2012.
Update per Tim Barnes: some years ago, HC told me "some Canadian called Ron" had been involved in the art. This is Ronn Sutton, who I emailed via his website to ask about his contribution. He advises
"The pages I penciled for SOS #3 were:
p.18 (penciled by me, inked by Dan Green)
p.20 (penciled by me, inked by Dan Green)
p.23 (penciled by me, inked by Walt Simonson) You can see my large initials R & S drawn into sword handle in first panel
p.24 (penciled by me, inked by Walt Simonson)
I inked almost all of pages 2, 4, 5, 8, 9, 10, 12, 16.
I also inked bits & pieces and half-pages elsewhere. In some other cases I'd sometimes I'd just ink a figure or two, or just ink a couple panels before moving on to the next page. I look at page 11, for example, and all i can be sure of is that I inked the Gray Mouser in panel 5 (but not the rest of the panel). Or page 13 where I inked panels 2 & 3 of Fahred & GM but not the rest of the page. But then you go to, like, page 16 and I inked the whole thing. Page 19 Berni inked the top half of the page and I inked the bottom half. So it sort of goes like that.... a figure here & there, a panel here & there, a full page here & there."