First of all, you should know that I really don’t want Hammond or “Jetpack Cat” to be Hero 27. I’d much rather prefer Brigitte or any other human or omnic. So, when I say I think hero 27 is Hammond, I have no bias and am not some fanboy. This theory is based on evidence.
Piece of evidence 1: The cat paw in the “Slaga” picture. This cat paw is completely orange. In the Reflections comic, we see the Lindholm family cat, and it has white paws. Either Blizzard made a large continuity mistake or the cat in the teaser image isn’t from the Lindholm household.
Piece of evidence 2: The measurements of the flail in the teaser image. It’s 32cm long. Even if you’re a smaller woman like Brigitte, that’s small. Go and grab a 30cm ruler and see what it feels like in your hand. It’s almost a knife. This makes me think that the mace is for someone smaller than a human.
Piece of evidence 3: Jeff said Hero 27 was hinted at. Brigitte was not hinted at, she was fully revealed and we’ve seen her in comics and shorts. Hammond, on the other hand, was definitely only hinted.
I can’t explain why the flail schematics are in Swedish, nor why the previous 2 teasers were focused on Torb. Yes, those things point to Brigitte being the next hero. However, there’s also evidence for Hammond/Jetpack Cat, and maybe they have some unknown connection to Torbjorn.