You are correct. The chance of the next giant dropping the earring is .4% (1/250). But this is exactly how probability works. If the chance of any one giant dropping the earring on any kill is 1/250, the chance of the earring not dropping on any one kill is 249/250. The chance of not having seen a single earring drop in 450 kills would be (249/250) ^ 450 which is .1647 or about 16.5%. If the earring drop rate per kill is in fact .4% (pointed out above to be in question), 83.5% of players killing 450 Forest Giant Greenwoods will have seen at least 1 earring drop and I would be in the 16.5%.

Ah, I thought you were trying to say that after 450, you should have a 16% chance of it dropping.

Nope, unfortunately when I go home to try this again later there'll still be a 1/250 chance of me getting the drop if I kill a single Greenwood. Doing some hack-math I think there's about a 1/125 of any one, non-ringband loot drop spot being an earring. Evergreens seem to have more loot per kill so I give my chance at getting the earring on any one of those kills at .6%. If that's true, I have a 93.4% chance of getting the earring before I kill 450 of those guys.

I put your chances of getting a forest loop drop at 32.333% chance (repeating of course)

I put my chances at 100% because at this point I'm obsessed and I'll kill ever damn giant in the game until I do.

I fucking hate this item. I’ve camped it over and over again and have never seen it.