Pre-1984, Takatoku Toys had a toyline that they called "Armored Insect Battalion Beetras", which was basically a line of transforming insects, pretty similar to the Insecticons' first release in Japan as Diaclone toys. The toyline can't have done too well, as Takatoku went out of business in 1984, and Hasbro bought a whole load of their toy moulds to use in the Transformers line. One of these was Beet-Zeguna, a black and brown coloured cicada toy, which Hasbro gave a much less muted colour scheme to, and released with two other toys as the Deluxe Insecticons.
Venom was released in 1985, and seems to have been an instant hit. So much so, that it would appear that people plyed with it to death, or just don't want to part with it, because it's impossible to find on the secondary market, at least for as decent price. They toy does look really cool though.
I always found it interesting that although they had little to no fiction, and that they were really only a footnote in the Transformers history, that Hasbro saw fit to include them in the back of the box art for 1985. So they're always there, they're always watching, but you never really notice them. They're like the monsters that you can only ever see out of the corner of your eye.
Sleep well, kiddies. Don't have nightmares.