Green’s Dictionary of Slang

(US) a man who proves more sexually enthusiastic, thus keen to fondle, than his girlfriend or date might wish; thus attrib.

1931		G. & S. Lorimer Men Are Like Streetcars 217: Come on, don’t be an octopus, Davy.
1952		W.R. Burnett Little Men, Big World 77: If I go in there, I’ll get trampled—or worse. That Mr. Riebe’s an octopus. If you hold two of his hands, he still seems to have six or seven more.
1957		(con. WWII) ‘Weldon Hill’ Onionhead (1958) : .
1967–8		Baker et al. CUSS 165: Octopus A strong, often offensive male.
1972		B. Rodgers Queens’ Vernacular 143: octopus disease the symptoms are fondling others in public places.
2001		J. Baker Shooting in the Dark (2002) 247: ‘You said there were two problems.’ ‘Oh, yes, his hands.’ ‘He can’t keep them to himself?’ ‘No kidding,’ she said. ‘The man’s an octopus.’.