TW: cannibalism because as you know by now luffy is a hungry hungry boi
The first time they see him do it is with Arlong - the first enemy with actual meat and muscle and no armor, who isn't a greasy circus clown.
It's the middle of the fight, and suddenly Arlong lets out a horrendous shriek. He sounds a like wounded animal, keening and howling and full of such horrible pain that every villager sinks to the ground with their hands over their ears – it is a sound that not one of them will ever forget. (How could one person that be in that much pain and feel that much fear?)
When they look up, there's blood covering every surface, sticky, red and glistening in the dim light (were those clouds there before?) The source of the blood, dripping slowly to the ground like poison, is none other than Arlong… and the gaping bite in his shoulder where his arm used to be.
Drip.
Drip.
Drip.
The one responsible for it is none other than Monkey D. Luffy, with teeth shark sharp and blood dripping down his chin. The arm, still stiff and hooked, disappears into his gaping maw, in the fashion of how a steak (eaten by a glutton, a carnivore, a monster) would be swallowed.
The terror hidden behind the guise of superiority now consumes the fishman's entire face. His eyes are wide and pupil's small, his face slack with an odd mix of shock and pain. The remaining hand brushes over the wound, shaking and weak.
It comes away bloody red.
(Fishmen and humans really do taste bleed the same.)
He takes a step back – then another, as Luffy slowly advances.
(Arlong is from the New World, and without Conquerors Haki, the Veil is settled over his eyes like a blindfold. He does not see the way the girl he trapped has a body of wind, how the woman he killed had a tail and horns perfectly curled, how every villager is most certainly not human. He knows but does not see – and now, he does not see the way the future Pirate King's eyes turn to slits and his fingers and toes sharpen, clicking as his body contorts into the shape of a predator – an apex predator. Arlong does not see the horns atop the other's head, peaking softly through holes in his beloved hat and the flashing of hellfire above them.
Arlong doesn't see, but Arlong is a Fishman, and has the instincts of a fish – a shark- and so Arlong knows.
He knows when something is not right, and the prowling shape, presence stronger than even the veil, that creeps toward him sends all his instincts screaming in pure terror. )
With the loss of a limb and terror settling in his bones, Arlong Park is soon nothing but burning, bloody rubble on the ground.
And Arlong is missing another arm.
(and something more)
Arlong tasted delicious. Luffy just wishes he didn't have to let him live so he could have eaten him all!
(But he had too – Luffy is no stranger to death, he has a lot of blood on his hands, and most of his meals are best eaten when the blood is freshly slowed – death is nothing.
Death is just a quick end to suffering.
To watch your dreams, fall apart, to have no chance to start again, to have a painful reminder of your failure for the rest of your life, to be alone and lost – that is the worst fate Luffy can think of.
And it is deserving of anyone who dares hurt his nakama.)
(Maybe he'll spread the message along)
It's alright though, because Arlong will never bother Nami again. His navigator will be as free as the winds and Luffy won't let that change – ever.
Here, in the dusty sea of Alabasta, slowly being swallowed by a whirlpool of sand – Luffy is hot and starving. He hasn't had a good meal in days. Weeks even. And Nami said he couldn't eat good meat (the kind he needed) when Vivi and Chopper were around. Not that he would, anyway – they have to save Vivi's country! There's no time for food!
But he's so very hungry.
And he knows he can't go too long without food.
(A harsh winter, unusual for Goa's climate. Little food, few people outside their homes. Hands frozen, blood on the ground – so much blood – and family staring in shock and horror but the hunger finally finally sated oh god-)
He wonders if the croc-guy will taste good.
Ooooh maybe he'll taste like crocodile! It's been ages since I had that! Nice, juicy, yummy crocodile!
Excited for crocodile meat, and finally out of the hole of quicksand, Luffy jumps back into the fray.
Its late into their battle when he finally gets a chance to dig in. He knows the Veil (its so different here than in the East, like its wrapped around him, oppressing, and harsh, rather than concealing the eyes of others,) is strong enough to conceal his presence (only now though – he will grow stronger-) so Croc-guy won't see what hits him. Surely his hits will land this time!
He unhinges his jaw, lets the dark texture of his skin shift into something less human, and lunges for that nice awesome juicy –
Dry, dusty, gross, sand!
Why is there sand? I HATE SAND! UGH!
He spits out the sand and turns to glare at Crocodile who is dryly amused.
"Expecting something different, beast?" He twists his hooked hand threateningly, but Luffy doesn't deign him with a response.
Instead, he looks closer, and growls at what he finds. Croc-guy's not human, not even close, but the Veil wraps differently around him, hiding his true nature from even one such as Luffy. He can see Luffy, but Luffy can't see him, not clearly. The man is a mirage, made of twisting mist and sand and fangs, and Luffy can't make out a thing.
(He doesn't know this, but that's what people see when they look at him – something shifting and monstrous but not in the way they know.)
"What are you, croc-guy?" He growls, and lunges again.
Sir Crocodile only smirks and lets his face fall away, blood pouring out of the slit face as a hook pierces Luffy's chest in shock.
"Oh."
He's like that, isn't he?
In Impel Down, the casualty rate is endless and pointless, partially because the Marine's don't care about prisoners except the ones on Level Four and lower.
It's easy to miss one or two – and in the heat of battle, it's easy to miss a limb or too, bitten off in the span of a second but a lifetime of pain.
And Luffy's so hungry – he ate so much on Hancock's ship and island, but the other Kuja Pirates were his friends and if a marine goes missing and does not turn up as stone…
Well.
Ace is waiting at the bottom of this Fake Hell. Luffy couldn't risk any stops.
He tries to old back he really does, but the beasts are already eating everyone, and maybe every meal is sickly and making him sick but –
(No food no life no control no family no friends you're alone alone alone foreverI)
He can't let that happen, even if he grows weaker and more tired and so so done.
He just wants to be with his big brother again.
(Ace would chain him up when they had no food, even when it was futile, and keep him company and make sure he didn't lose his mind to his own soul and hunger and beast.
Ace made everything better.
Ace-)
On Level Four, where fire roasts everything, Luffy sneaks away and gets a few meals.
It's not enough, and then he is poisoned, and then he is freezing and then Bon-chan is there and then –
Then Ivankov stabs him and he knows nothing more but fury and pain.
(And when he wakes, all that there is, is hunger)
Buggy knows what Luffy is, and can see the way his hunger drives him to shifting forms and glancing eyes. He's wary, as he should be.
Buggy think's the Strawhats are all insane, and not just because they are the Strawhats, who declare war on the world for one person.
(Buggy thinks of how his Captain died, and wonders if he could've fought it.)
No, he think's they are insane because they follow this particular demon from the East – Monkey D. Luffy is not like the rest of them, and Buggy feels the terror settle deep in his bones.
(Monster, beast, Demon, Unknown Loved, King of Beasts and One who Feasts – stay away, all who treasure, this one has learned from fae and fire and hunger the voice above his shoulder calls threateningly. )
It doesn't matter, as long as the brat gets them out of here.
And if Buggy has to divert a couple of eyes as Luffy snacks on one or more of their fellow prisoners, their screams blending in with the torturous cries of Impel down, well, the beast is their only way out.
Can't get out if it gives into the hunger afterall.
He thought he ditched him and left him to die, but he reappaears later with Mr. Two, covered in blood and with a feral grin. All but Ivankov are covered in blood actually, and the people of Ivankov's prison hide away give Luffy a wide. berth.
(Only Jimbe and Ivankov and Mr. Two dare tread close.)
Iva explains it later, when they are all on the marine ship, and Luffy is staring out to the sea.
He was hungry, you see, poor boy, and had gotten to three of ours before we got him some level two prisoners – some of the nastier ones, morally. Poor boy didn't care though, ate all of our food supply and any others.
I don't know how Dragon created that child.
Buggy sees the crown of fire above Luffy's head, and thinks that maybe Dragon didn't have much to do with it at all.
Luffy's learned his lesson – some fishmen taste good, and it's a bad idea to eat devil fruit eaters, and also Nami gets mad if he eats any of the important people they fight (such as that one big Marine guy, or that CP9 guy), because then it looks suspicious which Luffy does get, honest (Marineford had pictures of him covered in blood from the arm in his mouth, hidden away in case of public terror) but he's kind of curious.
"Mingo," he says, on the top of the fallen kingdom. "Are you made of string?"
"Fufufu! Why would I tell you that, brat?" Doflamingo's cackling voice responded, eyes flashing behind unseeing glasses.
"Eh," Luffy wipes a bit of blood from his lips, careful to avoid the sharp toothed edges that Doflamingo can't see, "I just wanted to know if you were tasty or not."
Silence surrounds the battlefield as the former War lord freezes in his tracks. His hands are poised like a puppet master with the strings of his puppets cut, and there is no movement save for the widening of his eyes.
He's scared, Luffy notes, for the first time in their fight.
(Enemies of God, the Celestial Dragons raise their children with this philosophy, The Will of D creates monsters who wish to defeat us, but they never shall – we are undeserving of that wrath!
Doflamingo remembers being pinned to a wall, and knows that the infallible Celestial Dragons are a lie which also means…
The East Blue is where creatures of the dark dwell, disgusting things. They consume all they touch, and chomp on the people without our protection – never let one near you, and if you do, destroy its teeth. It's the only way they won't bite the hand that feeds them!
Don't worry though, they can't leave the East Blue. That'd be ridiculous!
This creature before him has broken free.
And he's not stopping now.)
Luffy ponders what frightened the warlord so - Nami did say that eating things was different out of the East Blue – Rayleigh said that too.
(At Impel Down and Marineford, people stepped out of his way for more than his will. At Amazon Lily, it's a miracle Jimbe survived.)
He shrugs and starts grinning. It doesn't matter.
"I'm going to kick your ass." And get a snack either way, he snarls, and bites his thumb with his left fang.
Rubber limbs distort and fangs extend.
Mingo gulps, and fear permeates the air.
The puppet master falls.
(And string, Luffy finds out, does not taste as good as he thought it would.)