The female Palkia's from Nintendo's Pokemon and this screenshot's taken from Valve's Garry's Mod. It is made through  ArceusI's choice as part of the celebration of late Valentines and early Easter days.

Lady Palkia, from learning how Big Mama Rhydon builds up her Hydro Pump, tries out for herself and her belly bloats up, thanks to her practice. She feels quite bouncy, wobbly and proud of learning to store it up, even in a weird way.