I may have locked myself out of the hunters journal please help (SPOILERS)

[Grimug]

So i ended up getting the void heart before killing the boid tendrils since i thought you just had to avoid them didnt even think they were killable is there anywhere that they might attack me again or am i screwed.

[Hexamicor]

You find their journal entry in a way similar to the Goam and Charged Lumafly. Both of which can't be killed.

[Darc Vader]

Originally posted by McCramer:

You find their journal entry in a way similar to the Goam and Charged Lumafly. Both of which can't be killed.

This is correct. As far as I know, you can’t actually miss any of the journal entries. The only ones that would seem obviously missable are either interactable entries (see above) or are added to the journal immediately if you pass the point they become unavailable (all the White Palace entries).