A kaiju is only as big as the city you draw
Scale is not a property of the monster. It's a relationship, and it's built entirely out of the small familiar things at the bottom of the frame.
Draw a monster on its own and you have a monster. It could be four feet tall. Nothing in the picture says otherwise, and no amount of detail on the creature will fix that.
Scale isn't something a thing has. It's a comparison, and you have to supply the other half.
What actually makes something look enormous?
Small familiar objects, low in the frame, in a size relationship the eye can't argue with.
Helicopters are the workhorse because everyone knows roughly how big one is. So are searchlight beams, bridges, container ships, and lit office windows — a window implies a floor, a floor implies a person. The creature in the picture above is convincing because two helicopters near its shoulder are the size of insects, and because the buildings it stands behind have windows.
Remove those and the same drawing collapses into a nicely rendered lizard.
How is this different from cosmic horror?
Opposite methods, and worth being deliberate about which one you're making.
Cosmic horror works by refusing to show the thing — the horror is proportion plus ignorance, and a fully revealed creature kills it.
Kaiju shows you everything. The creature is fully rendered, centred, unambiguous. Its power comes from being present and physical — you can see the plating and the wet on it — while remaining completely indifferent to the city it's walking through. One genre hides the thing to make it unknowable; the other reveals it to make it unstoppable.
Mixing them gets you a half-lit monster that is neither mysterious nor impressive.
What should the creature be made of?
Something with a real material logic, not "monster."
The genre's best designs read as an animal that could exist: overlapping plates like a pangolin, keratin, wet hide, mineral crust, barnacles. Body plans borrowed from real creatures — an armoured mammal, a deep-sea fish, a crustacean — carry a plausibility that invented anatomy doesn't.
The practical version of this rule: name the animal you're borrowing from and the material the armour is made of. Those two nouns will do more than any amount of terrifying or colossal, which don't land at all.
Can it be a specific monster from a film?
No, and the boundary here is sharper than in most of this section because these creatures are strongly protected designs.
The silhouette, the dorsal plates, the roar, the name — those are property, and they're the first thing anyone reaching for this genre thinks of. What's free is everything that makes the genre work: the suitmation heritage, the burning skyline, the searchlights, the sense of scale, the tradition of a creature that is a disaster rather than a villain.
A new creature in this tradition is also simply better on a shirt, because it makes people look twice instead of recognising something instantly.
What about the city — how much of it?
Enough to give scale, and it has to belong to the artwork's own shape rather than being a backdrop.
The version that works: the skyline reads as a jagged base the creature rises out of, with smoke and light forming the outer edge of the design. The version that doesn't: a rectangular painting of a city with a monster in it, which reimports the border problem and reads as a poster transferred onto cotton.
A useful test — could you cut this out with scissors and have it still make sense? If yes, the city is part of the object. If you'd be cutting along a rectangle, it isn't.
Which city?
Yours, ideally. It's the single change that makes one of these personal.
The genre has always been about a specific place being visited by something indifferent — that's where its weight comes from. A skyline anyone recognises as their skyline does something a generic metropolis can't, and most cities have two or three buildings that make them identifiable in silhouette alone.
That's the version worth wearing, and nobody else has it.
How do I get one made?
Describe it at JustOG — the animal it's borrowed from, what its armour is made of, and which city it's standing in. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to order and shipped.
Designs other people have published are in the shop.
The monster isn't the hard part. The helicopters are.