What's the difference between the beast machines and beast wars versions? Are they just repaints? Plus is she rare?
The BM and BW toys are drastically different. The BM toy is purple and gold and is an original mold just for her so it looks female. It also features her 8 eye thing from the show and she doesn't look much like a black widow anymore. It's not that rare, and it was repainted twice for Universe. Her first BW toy, however, very rare. It was a Tarantulas repaint and it featured purple and green along with her TV black and gold colors, hard to come by because of the character popularity. Get the rerelease Takara is putting out now, black and gold at long last. She had a TM2 figure, too, which was her only show accurate toy for years and even then it wasn't exact. This one was molded just for her, too, so it looked very female. It was the biggest of the toys at $15 retail and was kind of short packed so it has some rarity to it.
I'd say BM Blackarachnia is the best of the bunch. Her spider mode balances nicely, and it isn't too cluttered. I may revise that opinion when I get the new Takara version, though.
