Two dwarves, "Udib Dishmabzuntir" and "Melbil Kibadek," who first appeared as migrants, showed up as @s and in the units list, are listed under "Others" as Hostile.
They're not actually hostile, as sending dwarves near them doesn't do anything. They just chill out around the areas they appeared at.

Retiring then unretiring the fort seems to fix this issue.

Other thing to note: Flying lungfish.