Rex Ryan of the Buffalo Bills is undoubtedly one of the most interesting head coaches in the NFL. Just in this offseason, he's jumped out of an airplane and had a corn maze designed after him, and training camp has just begun.

In an offseason that is seemingly endless with exciting news, Ryan is now going to eat a dog biscuit for charity. In what's being compared to the Ice Bucket Challenge, the Dog Biscuit Challenge is making its way around social media, and it's reached the Bills' head coach.

Surprisingly, Ryan doesn't seem fazed by the courageous act, saying he's "eaten a lot of dog biscuits" in his life. Just don't give him one of those big biscuits.

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"I believe I've been challenged to eat like a dog biscuit or something like that," Ryan said, via ESPN. "With the name Rex, obviously I've eaten a lot of dog biscuits in my day, so this is no problem. I accept the challenge. I thought it was kind of funny when I got challenged by this person, and I'm like, 'Alright, let's do it. It's on.' Give me one of them small biscuits though. I had the lap band [surgery], can't be the big ones, the large ones."

What a good sport Ryan is. Granted, it is for charity and a good cause, but eating a dog biscuit isn't something people do on a daily basis. The campaign will benefit the SPCA, which helps rescue animals. All around, it's a great gesture.

(h/t Twitter)