This Mufasa is the largest and most awesome plushie in my collection. This guy is HUGE. I put my 2011 Disney Store adult Simba next to him for one of the pics so that you all can get a better idea of his size; he's about 30 inches tall, his chest is 14 inches wide, and he measures 20 inches from his front paws to his rear.
So yeah, Mufasa's hugeness is pretty remarkable in itself, but he also actually looks like Mufasa did in the film, and that makes this guy the king of all plushies, haha. I just love him.
Anyhow, I believe he was sold at Disney theme parks, and you could also order him through the Disney Store online.
Sorry, but this guy is not and never will be for sale.