Empty spawn eggs or mob "boxes"

Basically, the deep dark isn't exciting, to fix that, we could either add something really good(better weapons / armor / tools) or plenty of pretty useful stuff, and the second one seems more exciting, so I'm gonna propose one of them:

Empty spawn eggs, crafted with echo shards, some other chest loot, and maybe another thing, like ores or another deep dark unique thing you plan to add. Now that you crafted the empty spawn eggs, you can right-click any mob that has a spawn egg and get the corresponding one. I think this would be a greatly appreciated feature for moving mobs or making it easier to farm relatively unique mobs. I think that the fact that the only way to move mobs is by annoyingly placing rails, ice or sail a boat on land is really annoying.

Also, maybe not spawn eggs, just some sort of "box" that allows you to capture the mob and release it so it keeps it's NBT data and doesn't modify spawner if it's to overpowered.