"Normal" lemons are mutants. They're a hybrid of two different Citrus species, citron and bitter orange, that both look weirder than lemons. In fact, one variety of citron, Citrus medica var. sarcodactylis, is nicknamed "Buddha's hand" and looks like this:

So what it appears (to me, at least, as someone who isn't a biologist or citrus expert) is that that lemon happened to mutate again in such a way that it started partially expressing an ancestral form.

I think it ate the lemon stealing whores.

biblically accurate lemon

When life gives you eldritch lemons, don’t make eldritch lemonade. Make life take the eldritch lemons back! Get mad! I don’t want your damn eldritch lemons, what the hell am I supposed to do with these? Demand to see life’s manager! Make life rue the day it thought it could give teft eldritch lemons! Do you know who I am? I’m the man who’s gonna sacrifice your family! With the eldritch lemons! I’m gonna get my engineers to invent a combustible eldritch lemon that burns your house down!

It’s a keming issue. An o got too close to the l and we ended up with a demon.

I’m no lemonologist but it looks like it could maybe be a very severe case of Citrus Bud Mites: https://www.inaturalist.org/taxa/384904-Aceria-sheldoni

Lemon flavoured tree cancer

Cthulhemon.

Thanks, buttpilgrim.

When life gives you lemons...

Demand to see life's manager.

Much like a rat king this should be known as a lemon king

The Rot

Lemon of the Crucible

Equip to make lemonade.

A vestige of the crucible of primordial life. Born partially of devolution, it was considered a signifier of the divine in ancient times, but is now increasingly disdained as an impurity as civilization has advanced.

Mutant lemon. If it tastes good, you should breed it and create a new product ;)

E.V.I.L.