Brendan Rendall is running a half marathon every day in June - and a full marathon every day in July.
In total, he'll clock up 1204 miles.
But if that wasn't hard enough - he's running in a variety of animal costumes:
Brendan can be seen running every day all around Salford and Manchester.
He says the animal costumes get a big reaction from passers by.
I've not made life easy for myself - it gets really hot in the costumes, and looking at the weather forecast it's only going to get hotter! The hardest one to run in is the rhino, because my leg stride is quite short in it. But it's bringing a smile to people's faces and ultimately, that's part of what this challenge is about. This year has been tough for everyone, and I just wanted to bring some laughter and some joy.
Brendan says it was a cause very close to his heart:
I've been working with children with special education needs for the last 12 years. I've been to the zoo with them many times and they've absolutely loved the day trips, and I absolute love it too! I also realised on my run across Africa quite how important conservation of endangered animals is - which is something Chester Zoo is amazing with.
Brendan will finish his marathon effort on August the 1st with a final run from Salford Quays to Chester Zoo - a journey of around 35 miles.