"So, how do you make a picture called Sharktopus?"

Roger Corman explains:

I started with this: The first one was DinoCroc and then DinoShark. And you could assume that there was a prehistoric crocodile and prehistoric sharks, so maybe there could have been dinocrocs and dinosharks. But there never was... a half-shark, half-octopus doesn't exist. So I had to come up with some way to justify this. My theory of this type of picture is, the audience wants to see it, based on the title, or they wouldn't turn on the channel.

Damn straight, I want to see Sharktopus.