@Colu
I think we are good now! The Leopard is eating normally, he swallowed a whole cube of blood worms yesterday. His hole in head is also gone and hasn't returned.
The puffer has only been eating snails. This morning I tried a frozen cube of cichlid delight and he ate it! I am also breeding shrimp and scuds for other live food options for the puffer.
But my tank is in a much better place. Thanks @Colu
Also, lesson learned the hard way. I now have a quarantine tank setup and ready to go. 🙂