If anyone else is still missing the tall herbivore, there is one on Efkad, planet of the Sivikmiyn I system (it's a rendezvous system, so you had to pass through it).
You're looking for a big gray insect creature with hairy legs and a thorax/head a bit like a mantis. It's rare, lives on ground, and is always active.
Found one! It was the first creature I scanned on this planet which is on the expedition path. Here are two imgur pics, one with the portal coords, one with the creature that got me the achievement.
I saw that the issue has been fixed so I just travelled here. I hadn't been here before so scanned this creature as a new discovery. I now finally have the achievement, thanks!
After doing some searching around it seems that unfortunately the ph level milestone is bugged.
The milestone and wonders page is actually tracking the highest ph instead of the lowest ph. I can confirm this with my own experience, my lowest ph was 3.6, I scanned another animal and got a message saying new record low but the ph level went UP to 4.2. I then scanned another animal and got the message again saying new record low and the ph level went up again to 4.3.
The only way to get this milestone done at the moment is to make sure that the very first animal you scan on a toxic planet has a ph below 2.5, otherwise you’re screwed. Hopefully they’ll patch this at some point.
I’ve seen ppl encountering this bug on xbox, PlayStation and PC, don’t know about switch but I would assume they have the bug too. Apparently if you’re on PC you can use a save editor to reset the wonder and then go to a planet where you know there is an animal with a ph below 2.5 and scan it first. Not tried that myself as I’m on Xbox.
Also, be careful. It has aggressive sentinels waiting at every corner. So best to land, get out of the ship, feel extremely hot and get back into the cosy ship. Leave and hope no one saw that.
Will do. If anyone finds these ones, post a planetary address, please. Can't promise I'll use it, but I don't want to fail this expedition. So maybe. 😄
Am looking primarily in green systems. There's a toxic planet in almost all of them.
the 'wonders' entry only updates with higher values, and the milestone wants 2.5 or lower, so if you scanned any creature with ph above 2.5 it will not be possible to complete at this time
The Ph Blood bug is fixed! Not only that, but you have already scanned a creature that qualified, just reenter the atmosphere of the planet where you scanned it, and the expedition will update and complete, even without landing. Can confirm this works on PS4.