I haven't humanized anyone in a long time but for some reason I REALLY felt inspired for young and old Mighty Eagle. For some other birds actually but I was more motivated for him. For the birds I will really try keep the beak shapes and length to make cartoony noses like I did with some dragons from Blazing Dragons
Supposing he is in his late 50's or early 60's in 2016 for the first movie, he must have been a teen or a young adult during the 1970's-1980's. I just felt like that as such, he needed a mullet and maybe ripped jeans and these open jackets with unfolded collars and ripped off sleeves. He would be so full of himself and his good looks he would not feel the need to wear a t-shirt beneath. But as an old man still very nostalgic of his gone glory days he would keep the mullet despite his hair bleaching and his tamples balding, and until the end of the movie where he would finally be back to action and put back his youth clothes (except the belt...), he would be too lazy to dress up or shave often. Also no need to precise his wings tatoo got very distorted lol
Sorry that's not the right shade of brown but the right pen is dying. Plus instead of flying... he would rather be the only inhabitant of the island with a plane or a moto or something

Angry Birds and Mighty Eagle © Rovio and Sony Pictures Animation
Ideas, drawing and human designs © me