oh my god this is so gorgeous! <3

I was thinking of pulling out the milky way, maybe it is too much clutter?
the milky way looks fine there in my opinion
Do you think the stars need more in quantity and umf?
maybe a bit of shine?
Is the tiger detailed enough to read as tiger, or is it too detailed to look like an aurora?
at first i thought it was a cougar, so maybe add some very light starry stripes to define it more
Would you buy this as a poster or print?
definitely a poster

I don't quite get the 'tiger' feel from this, more a generic cat or puma or panther or something. I always thought as tigers as large, almost scruffy animals, so you may not be able to get the exact definition. That aside, this is freaking AMAZING.

I don't know how much effort you plan on putting in on top of what you've already done there, but there's a few (visually) small things that can help you here.

Firstly, what type of location is this? Because if it's a desert or lowland mountainscape it's fine, maybe a little difference in moutain texture/bounce light. If it's a highland mountainscape you'll need some glitter or snow effect on there, or at least faint grassy texturing. (all effects/textures are faint too because it's night in the scene of course)

• I was thinking of pulling out the milky way, maybe it is too much clutter?

I can't really tell there is one in it, because there's way too many bright stars, I think? ..where's it at? If it's the horizontal band thing across the mountains you might have to redo it entirely because it's far more vertical from our earthly perspective, as far as I'm aware, perhaps it turns seasonally — more information would help.

• Is the tiger detailed enough to read as tiger, or is it too detailed to look like an aurora?

This is where I'm a little baffled.. it looks like you're doing a whole lot more effort than necessary here, because the aurora isn't that opaque normally. You could make the bottom outline a whole lot thinner and then more dense stripey patterns for tiger — also face and neck are a bit thin and such but that's all nitpickery. Another important thing to know is that the bottom of an aurora isn't a (semi-)solid line, but more like the top part, it's little reactions of waves hitting a magnetic "wall" and scattering from there, causing faint light to appear, not so much lines shooting up from the atmosphere.

There's also different auroras, so depending on the location you're watching from, the colours will differ. The northern one is mostly green-yellowy to blue/ultraviolet and the southern one is more orange-reddish to infrared, both do have a fade off though, but neither has a full spectrum. I'm not entirely sure if you've been staring at both poles' auroras in your refs and ended up with a rainbow because of this.

Also keep in mind that most aurora images, such as photos and videos, have been enhanced by filters and lenses and auroras are just wisps to the naked eye. Most of them look like that one at the very bottom, just over your mountainscape, and sometimes the solar storm is strong enough to make them as visible as it is on the very top. They mainly depend on frequency to show up and if they don't move fast enough (as they normally don't) you don't really notice them — much like vapour fogs and cirrus clouds. Most photos are long-exposure shots and most videos are timelapsed, which tends to mislead.

As for it looking like a tiger, it certainly has feline properties, but I guess a bit stockier would help around the neck. This is of course all dependent on references used, species and style. Not all tigers are the same and it still is a work of art, not a recreation of life, some artistic liberty is allowed.

I really love that you used a star for the eye as a little personal touch, and I definitely love the effort of putting at least some constellations in there, or at least so it seems. Whether that's the right sky for the right location I'll leave to Neil Tyson :P ..this looks pretty amazing and a lot of work as it is. I'm sorry if my crits negated all your work or sound like you have to start all over ..please don't feel obliged or discouraged :\

It looks like the exports has given their advice (or at least more experted than I am)... my fave is my critique. this is beautiful. The only thing that I myself pick about is the lack of stripes makes it so you can't tell it's specifically a tiger (as everyone else has said) but if someone likes mountain lions, or panthers more than they can enjoy it just as well too! The other thing is that line on the haunch that makes it look like the animal is breaking/broken up. I'd rather it be a solid animal myself if it were one I was extra fond of. I also think there are too many large stars. Personally I feel there should be a few large stars, a pawful of bright stars, and a scattering of faint stars.