A little deer sticker for the drivers door? https://www.carstickers.com/products/stickers/animal-stickers/deer-car-stickers-decals/ alternatively I'd cut it out and weld a new bit in as Paul said, but check that it's not twisted it as well.
generally to repair damage you have to reverse the impact, so super glue a deer to the dent and pull it out!
The standard way of repairing similar dents in musical instruments like trumpets is to force a series of balls of increasing diameter through the tube. Clearly, not practical in this case, but just saying...
drill a hole opposite the dent....and use suitable rods to press the dent out, with the pipe set against something solid or half round so you don't go too far. Then weld up the hole.
I tried the weld/slide hammer method. got it pretty damned close, but since the tube was quite thin and i might have been a little over enthusiastic with the slide hammer, there was a couple small tears round the edge of the welds as i pulled on it. Finished the shaping with a wee bit of chemical metal Obviously there was no chance of keeping it stainless, so It's now a lovely satin black, but below is a pic after a good blasting all over with a 36 grit roloc and a couple decent coats of epoxy primer
It would have been delicious. A youngish stag and instant wipeout- completely Adrenalin free. I went to the scene 30mins after for a look after consoling the wife, but it was gone. The two kind gents that helped the wife out likely had it away, and i would have done the same!
I was in a car in germany and a deer ran across in front and jumped. it came through the windscreen totalled the new car and I got cut in the face .eating it was the last thing on our minds
A mate where I used to work and myself had delivered some fliers to the castle in Inverary and were heading home in the van when one jumped into the side of us. Made hell of noisese and put a big dent in the panels. We got out and it was struggling to get up but 1 front leg was smashed and the other was looking broken so we used a rock to send it on it's way. We gutted it there and left the guts to the foxes, got home and peeled it and split it between us. I was sick of eating the stuff and edged up feeding a fair bit to the ferrets.