Easy tame - zip line, tanky ravager, handful of hazard helmets. Aggro, have line already placed at angle so you can adjust elevation above the basilisk. Jump on line near basilisk while he is biting, and inch up just until the bite barely stops reaching you. If you do this right and don’t put too much distance between you and snake he will keep biting and missing, and will not fire the gas and will stay there the entire tame while you drop eggs (FROM YOUR PERSONAL INVENTORY NOT YOUR TAME). Basically you’re staying between his two attack ranges. As long as no wild critters aggro him away you will get perfect tame. In an ideal world have a partner maintain a perimeter clear of wild dinos.
Seems like raising a rock drake 1st will help you tame these. 1st raise a drake. 2nd collect a bunch of rock drake eggs. 3rd find a basilisk and while riding the cloaked drake drop the eggs one by one and it will eat them.
Actually the Basilisk only eats Rock Drake fertilized eggs. The wiki says that it should also eat other fertilized eggs, but currently it ignore them. Probably it's a bug, for now feed it Rock Drake eggs
3 min 30 second feeding interval it seems. I have better taming effectiveness by keeping it aggroed while running it in circles. Lvl 20 only took 2 eggs. Lvl 85 took 4. Drop 1 egg. Aggro. Let it feed. Start stopwatch. When ready to feed it rears up n screams but does not spit
Get yourself a Rock Drake, Karkinos, Spinosaur or any other creature usually ignored by this creature, dismout to gain its attention and mount again; Drop the Rock Drake Egg from YOUR inventory and proceed to circle the Basilisk until it looses interest on you. Wait for the feeding interval to end, repeat.