i put this green rope on two angels holding hands, what did that do?

[CLipsAhoii]

i didnt here any unlock or nothing, does this change an ending or something?

[VonFIDDE]

Did the same not sure what the point was :0

[Aria Athena]

You need to beat either of the world's last bosses. Depending on which one you kill, you get a different neck.

Edit: Apparently this is wrong

[Rinny]

You just need to re enter the zone
There are two dif color ribbons you can get that give a dif item (has nothing to do with the boss)

[Billy Blaze]

Some information is completely wrong.
You don't have to defeat the last boss of that world... you just have to come back at a later time.
I used the rope, cleared the dungeon, came back to it without even leaving the dungeon and got my reward.

EDIT: Don't know if "not leaving the dungeon" is true, since I sometimes warp back to the hub.
But I still did it without doing anything else in this world.

[Angelus033]

Leave the area (via door or teleport) and come back
You'll get one of the two ribbon at random

[Toon]

After you put the ribbon on their hands, if you reload the area you'll get a silver ribbon or a gold ribbon. Which ribbon is determined on whether you're in the light version for gold or the dark version for silver.

[Aria Athena]

Originally posted by Ang3lus033:

Leave the area (via door or teleport) and come back
You'll get one of the two ribbon at random

At random? How is this not tied to the last boss? Seems like a very obvious reference.

[Drake]

Yeah it's not random, the light version gives the golden ribbon, the dark version gives the silver ribbon.