I did alittle research into the creature and these are all the abilities I came up for it that'll seem suitable for a massive beast like this. So I wanted to give it a cobra look to it since it's an old world creature and it may have been based off of the King Cobra since Europeans traveled to South East Asia, but i also gave him some viper qualities too. So yes he has a hood but with spikes on the edges and since he is the kind of snakes, i gave him a big "crown" on his head with big antlers to add to the majestic look. Plus since he can kill with just his gaze, i decided to give him the skeletal coloring to make him more intimidating. His colorations on his body are the skeletal looks are white, tail spikes and crown and antlers are black, mainly his scales are purple.

So bio
Length: 300 feet long
Weight: 100 tons
Speed: 40 mph, 50 mph swimming
Abilities: He can spread his hood and rattle his scales on them to create a rattlesound to stun creatures, the two openings on his snout are his pits for sensing heat
he is resistant to poison/venom, heat and his scales deflect most conventional attacks. He hates bright light and is weak to cold below freezing, his tongue not only acts as a sense organ but also as a grabbing tongue or can manipulate objects. His venom can spray up twice his length and melts almost anything and it intoxicates the area its sprayed or can melt any creature he bites that is smaller than him or can heavily weaken bigger creatures unless they have a powerful healing factor. and of course, his signature move is his stare can kill, but he has two levels of his stare he can use. He has 2 retractable, see threw eyelids. when both are covering his eyes, it is safe to look in them, when one is pulled back, he can paralyze victims, but when both are pulled back his stare can kill
and he is immune to his own death stare affects, so mirrors dont work. Plus his coils can bend steel and bend dragon scale

Bio: upcoming..