No it couldnt. Victims of the poison headcrab have three poison headcrabs sucking them. The only way would be to import the model with Sharper and dupe the crabs, but a lot easyer way to do this is to make your own.
I meant just one, I totally forgot about the riding 3. When I get a modeling program, I'm gonna try to make my own like you said, but only for me to use.