How do you scan the Earth Leviathan (Giant Worm)?

[SlayerPlayerNate]

My goal is to get every codex and bestiary entry and I cannot figure out how to scan the worm. Is there a trick to it, or is my timing with the scan just bad?

[gabriel_von]

Try walking around outside, when the Leviathan is about to come from the ground, stay next to the death zone and spam click the RMB. At least that is what I would do.
Good luck with your quest.

[Howard Roark]

Personally, I wait until it attacks, then spin around, look up, and RMB. Usually works for me, though sometimes I miss it (and sometimes I mess up the timings and get eaten).