If you try to go though a nether portal with a parrot on your shoulder, it will act like you are standing in an unlit portal frame, and will not let you go to the nether.

Expected result:

The player would be able to travel to the nether while having a parrot on their shoulder, just like if they would normally go to the nether without a parrot.

Actual result:

The player steps into the portal, and the portal doesn't transport them anywhere. The screen doesn't turn purple and it doesn't warp your vision.

How to reproduce:

1.) Get a tamed parrot on your shoulder.

2.) Walk into a nether portal.

This may not affect many people during normal gameplay, but if you are trying to transport parrots or just want to bring them along on an adventure, you can't easily do it.