Grolls

From Glen Cook Wiki

Grolls are described in Sweet Silver Blues as a hybid of human, troll, and "The Beast That Talks that is not named in polite company." Later, Grolls are described as part troll, part giant. They are about 20' tall with pale lime-green skin, and have wide, frog-like mouths. They have a little-known natural camouflage ability that enables them to change colors like a chameleon. Typically, they wear only loincloths, which don't conceal all that much. Like many mixed-breeds, they do not seem to handle alcohol very well.

Minor quibble - the grolls we know about, Doris and Marsha, show no ability to speak or understand human speech - until Angry Lead Skies. Then, they're quite conversant. But then, what's a little deus ex machina between friends? (Sweet Silver Blues, page 47). Also, in Whispering Nickel Idols, Garrett describes the grolls as only 12 feet tall.