Cultists and cockroaches

I've got two questions. 1) I have the current CSM combat patrol is there any way I can make my cultists more malice'y 2) the malal demons that were in fantasy had this one that was a mount that kinda looked like a cockroach. Im a huge Papa Roach fan and I think it would be sick to have my lord discordant or lord on bike riding a giant deamon cockroach. Does anyone know where I could get a cockroach esqe miniature to be a mount.

Thank you.