Addictive Tips shares a detailed guide to swapping out your boot animation by either downloading an existing alternate boot animation or creating your own. One of the nice things about the technique is you can do it on both rooted and unrooted phones–the difference is users with rooted phones can save the boot animation in a system directory where it will persist after a hard reset.
Hit up the link below for additional details as well as some sources to find boot animations.
How To Change, Customize & Create Android Boot Animation [AddictiveTips]
