"Ropers inhabit subterranean caverns. They prey upon all forms of creatures, but humans are their favorite form of food. These monsters can stand upright in order to resemble a pillar or stalagmite or flatten themselves to full length upon the floor so as to look like nothing more than a hump. The roper has six strands of strong, sticky rope-like excretion which it can shoot from 2'-5'."
"This yellowish gray monster appears to be a mass of foul, festering corruption. The roper is cigar-shaped, about 9' long, with a diameter of some 3'."
Gary Gygax, Monster Manual I