Frog Prime? I don't remember him bein so time consuming, but I could be wrong. For King Jelly, it would be a matter of either using d-form or enegy form and beast form when necessary since eating the little jellies would be time consuming, but it could end up being necessary if there's too many.
I'm gonna give Mithalas a go, does anyone know if he has to be pushed all the way back for him to use his suction attack?