How do I reduce the cpu usage of the monster aminations

Hi all! I am using a program called spiriter pro. It's very good program to make aminations with complicated body moves. I understand that this forum may a wrong forum to send my questions.

My problem:

The game's CPU usage remains at less than 11%. It's a big game and I am very satisfied with the number. After creating 50 same monsters in the screen and every aminations is pausing. The CPU usage does not increase very much. After a moment, the aminations begin playing so the engine suddenly increases by like 30-40%.

The aminations from the spiriter pro is not very compressed and not vector art. The file name is png. The prictures is a bit too big. Can it affect the CPU usage?

Is there any solution? Have I to reduce the amount of the monsters?

Thanks!! And sorry for my bad English!

Just a few tips:

Make sure they're all on the same layer

Check the size of the sprites animations, if they're big make smaller.

Remove any effects

Large pictures can effect CPU do to scaling and redraw times