He was motivated as much out of sadistic pleasure as he was by greed. McLeach sought to capture a rare eagle, and was ruthless enough to use a young boy named Cody as bait in order to get what he desired. Unlike the comical Madame Medusa of the first film, McLeach was shown as a serious villain with no redeeming qualities and was so utterly psychotic that he was willing to feed Cody to a swarm of crocodiles once the boy had outlived his usefulness.
McLeach was first introduced to Cody when the boy fell into a pit-trap after he befriended a rare and magnificent eagle known as Marahute beforehand. The boy still had one of her feathers as a parting gift - which would prove to be a mistake as McLeach noticed the feather and decided to kidnap the boy to help him track down the eagle (though McLeach was also intending on kidnapping the boy regardless, so as not to risk being found by the authorities).
McLeach proceeds to toss Cody's backpack to crocodiles to trick the rangers into believing that the boy had been eaten by the animals and thus covering his tracks - meanwhile Cody is driven to McLeach's lair where he is soon put in a cage alongside a collection of rare and protected Australian wildlife, many of which are living in terrible conditions.
However, Cody is in luck as two mice from the Rescue Aid Society are soon sent to aid him, being none other than Bernard and Bianca, the heroes of the first film - upon arriving in Australia the two mice become aware of McLeach's true plan once they track him down.
Knowing that Cody was emotionally attached to the eagle, McLeach cruelly lied to the boy, telling him that Marahute had been shot by another hunter and thus nobody was around to guard her eggs - however this was an act and when a worried Cody runs off to find the eggs, McLeach follows in a large truck, he also brings along his lizard sidekick Joanna so that she can eat the eggs and thus ensure McLeach gets even more wealth via making Marahute the last of her kind.
McLeach proceeds to capture Cody and Marahute, taking them to a cliff where he ties Cody up and decides to feed the boy to a swarm of crocodiles since he had outlived his usefulness - but Bernard manages to stop the machine McLeach was using to lower Cody into the river.
McLeach responded by getting out of the vehicle and personally started firing at the rope holding Cody with a shotgun, but once again Bernard thinks fast and tricks Joanna into chasing him - causing her to knock both McLeach and herself into the river in the process.
While in the river McLeach is attacked by crocodiles, but he fends them off. After a while, the crocodiles departed and McLeach taunts them triumphantly. However, as McLeach turned around and notices Joanna waving good-bye, he realizes that the crocodiles were not actually afraid of him, but were swimming away from a huge waterfall. McLeach panics and tries to escape, but is swept over the falls and plunges into the river below.
- He was voiced by the late George C. Scott.
- When it comes to his clothes and weapons, he resembles the Sniper from Team Fortress 2.
- Percival C. McLeach will become Simba's enemy in Simba, Timon, and Pumbaa's Adventures of The Rescuers Down Under.
- Percival C. McLeach will become Ash Ketchum's enemy in Ash's Adventures of The Rescuers Down Under.
- Percival C. McLeach will become Tino Tonitini's enemy in Weekenders Adventures of The Rescuers Down Under.
- Percival C. McLeach will become Littlefoot's enemy in Littlefoot's Adventures of The Rescuers Down Under.
- Percival C. McLeach will become Bloom's enemy in Bloom's Adventures of The Rescuers Down Under. And in the film, he will reveal to be an old time enemy of Ariel.
- Percival C. McLeach will get his revenge on Bloom, Ariel, and their friends in Bloom's Adventures of Big Hero 6, Bloom's Adventures of Descendants, and Bloom in Fantasmic!.
- Percival C. McLeach will become SpongeBob's enemy in SpongeBob and Friends Join The Rescuers Down Under.
- Percival C. McLeach will become the Fantasy team's enemy in Benny, Leo and Johnny's Adventures of The Rescuers Down Under.
- Percival C. McLeach will become Thomas and Twilight Sparkle's enemy in Thomas and Twilight Sparkle's Adventures of The Rescuers Down Under.
- Percival C. McLeach guest starred in Danny's Adventures of Beauty and the Beast, when he made his first ever appearance and was revealed to be Darla Dimple's Uncle.
- Percival C. McLeach appeared for the second time in Danny and the Emperor's New Groove.
- Percival C. McLeach's last appearance will be in Danny Joins the Rescuers Down Under.
- McLeach returns in Thomas and Twilight Sparkle's Adventures of Open Season to get vengence on Thomas and Twi's team. And is more than determined to get their pelts or sell them as pets.