Arcanine and the Growlithes are from Nintendo's Pokemon and this screenshot's taken from Valve's Garry's Mod. It is done through Blairscartoons's choice as a celebration of Pokemon Day.

After this Arcanine parent enjoys eating lots of apples and such, it's Growlithe children came to play with it's belly and it's very glad to see them having fun with it. Whether this Arcanine is a mama or a daddy is up to you guys.