Sims 4 Vampire Discussion: I Need Help

If you want to use frogs you can breed them in your inventory, just click on them in the inventory. As soon as you have two, they can create a new frog every few hours. There is a cool down of a few hours but as long as you keep two in your inventory you can create a plasma pack every few hours after breeding a frog. It's not enough to fill all the vamp thirst, but you need to buy less packs on the pc.