***By Using Photoshop precisely cutting on picture can be done***
apps all you need
photoshop
whatsapp sticker manager = https://play.google.com/store/apps/de...
you can do this on any other app also i preferred photoshop cc 2015
but just remember to save to pic in .png format after editing it
if you want other stickers just simply search .png format images on google and grouped them together in single folder and add them via whatsapp sticker manager.