Which is the most useful mob?

I can't tell you how many times a trader asked me for 3 emeralds in exchange for a LILY PAD.

That's because you can't always find lily pads. What if you're in a buffet world or a superflat? The only other way to get them is from fishing, and until recently, lily pads were considered a treasure item.

What if it isn't buffet or superflat? Just go to a swamp and profit.

But not everyone has access to a swamp biome, especially not in the aforementioned scenarios.

Lol

4 emeralds for 1 slime ball. On my survival world.

Slime balls are useful in a way (slime blocks can save your hide).

4 emeralds.

Why is getting a slime ball for four emeralds a problem? You could just give him 36 emeralds and he’ll give you 9 of them so you can make a slime block.

It's in survival and we've only found 3 emeralds total

I mean, if you can't find a swamp or slime chunk, that's nice.

4 emeralds tho.

Yeah, but unless you're using the slime for something else like a slime blok and not a lead, you can just kill the trader for 2 leads for free.

What do I do with the last lead-

They are only useful for getting free leads

One useful wandering trader encounter I've had was when I traded for sea pickles and coral blocks so that I could grow the sea pickles, and then use them to brighten up the river.