Again HaShem told Moshe to warn Paraoh that another plague was coming.
So Moshe went to Paraoh and said, "Now your land will be overrun with all kinds of fierce, wild animals!"
Soon, out of the desert came lions and tigers and bears - oh my! - and snakes and scorpions, and all sorts of other dangerous creatures. They were everywhere - except in the Jewish town of Goshen.
The Egyptians were terrified, and Paraoh quickly called for Moshe and Aharon.
"Enough! Enough!" cried Paraoh. "I'll free the Jewish people. They won't be slaves anymore! They can sacrifice to HaShem right here in Egypt!"
"Sorry, Paraoh," said Moshe. "That's just not good enough. We need to go into the desert for three days to make our sacrifices. After all, we'll be sacrificing lambs, which you Egyptians worship... and you wouldn't really want us to do that in Egypt, would you?"
"Fine!" said Paraoh. "You can go into the desert for three days -- just don't go too far away!"
"I'm so glad you said that. I will pray to HaShem to take away all of the wild animals tomorrow."
The very next day, every single one of the animals left. (They disappeared from Egypt completely; they didn't just die, because dead animals would have been valuable to the Egyptians as meat or leather or fur.)
But stubborn old Paraoh cried out, "NO!! I changed my mind! I will NOT let my slaves go!"
(Did you really think Paraoh was the type of person who would keep his promises?)