I coded some custom loot tables for mobs in 1.11.2 to allow for the drop of their spawn eggs. Jumped over to 1.12 and I get a new error that does not allow for mob identification in the following line:

Original code: "tag":"{EntityTag:{id:minecraft:creeper}}"}

It gives the following error:

Expected '}' but got ':' at: {EntityTag:{id:minecraft:<--[HERE]

Attached is my .json file for a creeper to drop it's spawn egg along with it's mob head, but this error happens to all altered loot tables regarding the drop of mob eggs.