The latest social-media frivolity this week from the man known as Roaring Kitty sent traders frantically reading into a cartoon featuring, of all things, a dog. Was Keith Gill getting into WOOF? (Petco Health & Wellness Co.) Perhaps PET? (Wag! Group Co.) Or, quite possibly, the company that was co-founded by Ryan Cohen, GameStop Corp.’s current chief executive, CHWY? (Chewy…