I had loads of seeds on the ground for him before; the aggression happened before a rollback originally, I had simply disconnected from the server and reconnected. There's no way it was because he was hungry due to the seeds I spawned in so he didn't starve while I was trying some things, and I hadn't done a rollback before the original aggro, I had to kill him originally as I didn't realize what was happening so figured rolling back wouldn't do anything other than fix the issue or reproduce it to record...
I closed my server to double check the length of my seasons; when I opened the server again (less than a minute or two later) the smallish tallbird I had hatched immediately aggroed onto me upon spawning in, and wouldn't stop trying to attack me. I originally thought it was because they had grown into a normal tallbird, but they were still a smallish tallbird, and I was still able to offer seeds for food (although they wouldn't take it and immediately attacked the second I got close enough). They had not been aggressive immediately before I disconnected. Active Server Mods: Global Positions; Mineable Gems; Multi Rocks; No Thermal Stone Durability; Show Me (Origin); Simple Health Bar DST; Recipe Randomizer Active Client Mods: ActionQueue RB2; Combined Status; Geometric Placement; Minimap HUD I rolled the server back and grabbed this clip from respawning in https://va.media.tumblr.com/tumblr_qsb8p3YJNC1z1f0gq_720.mp4 Sorry if I'm missing any details, my brain is so scattered tonight