When Hermione asks what the Pygmy Puff's name is, just type in what you want its name to be. To feed the puff, click on "Feed your Pygmy Puff", then click on the bananas or apple to decrease hunger or the water to decrease thirst. To make your puff happy, click on "Play with your Pygmy Puff", then click on "throw ball" or "jump around". Have fun! Press the space key for your Pygmy Puff to be able to play with Crookshanks (Hermione's pet cat)
Thank you to @sapphire10fun for the idea. Thank you @babanor for teaching me to Scratch. Please comment with new ideas for the pygmy puff. BTW I always name my pygmy puff Cheez Puff.