he died and while i was fighting a Strider, and now he is invincible after he re-spawned, and also has a hat, and I can't replicate it now

https://i.imgur.com/qiF1vLl.jpeg

edit:I THINK I FIGURED IT OUT, from what i know its like an upgrade, and makes him either invincible of have more health, he also dose more damage it think, and his ability where he gives you shield now quicker, if it is disabled it looses the upgrade

So in summery, the Vorti follower will get a chefs hat and an upgrade when a Strider boss is killed when they die (if they even can) or when they are are disabled, they loose the upgrade and hat