I have fond memories of spending 4 days in Darwin and a whole day on a 'Kakadu National Park tour' in 2007...and so thanks for uploading your recent batch of photos. I didn't stay at this hotel but I can clearly recall seeing it.
It's a very large and distinctive part of Jabiru town so if you're around Jabiru you're likely to see it. At night the eyes even light up red, which is rather ridiculous but doesn't really feel any more ridiculous than having the whole hotel shaped like a crocodile.