I always try to have all variant of minifigures So, when i check bricklink, there are total of 6 variant of Doc Ock! But i cannot afford to have all variant, because of the price =p. Here's the pic of my Doc Ock =) The other variant that i don't have is really similar to the 2nd from left. For the other 2, the torso is the same, but only face print is different.
The one on the left is from set 4857 - Doc Ock's Fusion Lab - year 2004
I just add them to my wanted list. maybe i just grab it if i accidentally found them when placing order for other parts.