The title says it all, let's go.

Animals

P-51 Mustang: Although made popular by both the plane and car, a mustang is in fact a kind of horse, hence why it is the Mustang logo (car).
P-40 Warhawk: Admittedly, there's no such thing as a Warhawk aside from the P-40, but it's still a hawk. Believe me, this way of thinking is going to come into play for many of the animal-named planes.
F4F Wildcat: They just took a cat and put "wild" in front of it.
F6F Hellcat: They just took a cat and put the funny h-word in front of it
F7F Tigercat: They just took a cat and put "tiger" in front of- wait, a tiger is a cat, so the Tigercat is the cattiest cat of the many cat-named planes.
F8F Bearcat: They just took a cat and put "bear" in front of it.
F9F Panther: Named after a cat, but because the military must sound intimidating, they named it Panther instead of something like Calico.
F9 Cougar: Ditto, but they named it Cougar instead of Calico.
Digression: WHY ARE SO MANY WWII PLANES NAMED AFTER CATS?!
B-23 Dragon: Dragons certainly aren't real, but they are still animals.
Me 262 Schwalbe: Schwalbe is German for Swallow, in this context referring to the bird.
De Havilland Sea Vixen: Basically just a fox, but from the sea. Again, foxes don't live in the sea.
Yak-9 Yastrebok: Yastrebok means "little hawk," I guess even the Soviet Union needed a plane named after an animal, as all the major world powers did during WWII (I guess Italy and France can be an exception, but I'm pretty sure their allies gave them planes named after animals, right?). Wait. America, Germany, Britain, Russia... where's... Ja-
Ki-43 Hayabusa: You thought Japan could escape naming a warbird after an animal? Hayabusa literally translates to "peregrine falcon" (actually just falcon, but commonly peregrine). That's definitely an animal.
P-39 Airacobra: A cobra, but in the air, how nice and ssssssneaky of a name.
P-63 Kingcobra: Literally named after an actual snake, but they forged it into one word because... I don't know, I'm not Bell aircraft lol.
Fairey Swordfish: Named after an actual animal, the swordfish. Makes sense, except the Swordfish looks quite... odd, to say the least.

Any inanimate object in nature

-P-38 Lightning: Pretty sure I don't need to elaborate here.
-J2M Raiden: Raiden means Lightning Bolt. I know what you're thinking, even if you don't know what you're thinking.
-P-47 Thunderbolt: No explanation needed here either. Notice how I put thunder after all the lightnings though (haha)
-G8N Renzan: My research says that Renzan translates to Mountain Range. Quite cool, but I'm pretty sure mountains aren't alive and sentient.
-De Havilland Mosquito: This should fall under the animal category, but I think at the end of the day, we'll all agree that mosquitoes are soulless monsters that shouldn't be classified as living creatures.
-Gloster Meteor: Although we rarely think of things like this, Meteors are formed and in nature. Not to worry though, they're also inanimate!
-FR-1 Fireball: Fireballs might be a little less natural, but fire itself is in fact a force of nature.
-Hawker Hurricane: It's literally named after a natural disaster.
-Me 163 Komet: Unsurprisingly, Komet is German for comet. Comets are natural, at least last time I checked.
-P-80 Shooting Star: We may have seen shooting stars before, but have we ever realized that they're part of nature?

A Title/Type (for a/of person)

-P-26 Peashooter: I think a Peashooter is more of a gun, but like the term "sharpshooter," I'm guessing a peashooter could also be the actual person who shoots peas (Monarchii, beware!!!)
-TBD Devastator: Technically speaking, a devastator is a person, right?
-BTD Destroyer: If you destroy, you are a destroyer. Thus the Destroyer is named after the average toddler with toys.
-TBM Avenger: Albeit an avenger is still a title for a person, the Avenger was not named after everyone's favorite assembled heroes. In fact, it's the other way around; the first Avengers comic wasn't made until 1963, while the WWII vet was made in the 1940s!
-SBD Dauntless: Albeit more of an adjective, Dauntless can still be considered a type of or title for a person.
-B-24 Liberator: If I'm being honest, I can think of no context external to the B-24 where the term Liberator could be used, but I'm sure it exists.
-A-26 Invader: I think we all know what an invader is, I shouldn't have to elaborate (but I will anyways because I'm a reliable sauce). The A-26 is literally named after a term used to describe one who invades.
-B-26 Marauder: A marauder is basically a raider, but much more violent.
-A-1 Skyraider: Basically just one who raids, but in the sky.
-F4U Corsair: A corsair is essentially the same thing as a pirate or pirate ship. Quite fitting, on account of the fact that the Corsair is a Navy plane.
-SB2U Vindicator: A Vindicator, by Dictionary definition, is "a person or thing that clears someone of blame, suspicion, doubt, or the like, or that proves someone right through evidence or argument."
-A-6 Intruder: A person who intrudes into territory that is not their own, need I say more?

Other intimidating stuff

-A-20 Havoc: Havoc meaning mayhem, what's more intimidating than an aircraft that causes absolute chaos amongst its foes?
-IL-2 Sturmovik: Sturmovik literally means "ground-attack aircraft." Anything but creative, but not too bad.
-Ju-87 Stuka: Short for Sturzkampfflugzeug, which is literally German for "dive bomber."
-De Havilland Vampire: Not quite a type of person, nor an animal, so I put it here. Vampires, you know what they are.
-Yak-3 Ubiytsa: Ubiytsa translates to killer, which would make sense provided that the Yak-3 managed to actually shoot anything down.

None of the above, but still makes sense

-B-17 Flying Fortress: It's literally a fortress, that flies. In a more specific sense, it's very durable, very well armed, and very big, which is everything something needs to qualify as a fortress.
-B-29 Superfortress: Eh, just a Flying Fortress but super. Skit;
B-17: "There's not enough room in this airspace for two super fortresses!"
B-29: "Oh you're a Flying Fortress alright, just not a SUPER one!"
B-17: "Oh yeah? And what's the difference?"
B-29: Insert Little Boy bomb here
B-17: "W-wait-"
B-29: Insert Fat Man bomb here
B-17: "OK OK, fine, I give up, you win."
-B-18 Bolo: Bolo could fit in Other Intimidating Stuff, only issue being I'm not sure if the Bolo is named after the military/police term Be On The Lookout, or after the swordlike weapon, so for now I'm just putting it here.
-F-86 Sabre: Sabre being a type of sword or bladed weapon. Really should just make a "named after weapons" category, but it would be a small one to be frank.
-Bf-109 Messer: This is a tough one, being a given nickname, but it can either mean one of two things; short way of saying Messerschmitt, the 109's manufacturer, or German for knife. Either works in this context.
-Supermarine Spitfire: Yes, I only know him by his gamer tag, but that doesn't matter, point being that Spitfire likely references the fact that it spits bullets like Matpat spits facts. Should be intimidating, but I put it here cause why not.
-G4M Hamaki: I was gonna put it in "intimidating stuff," since one translation reads Hamaki as "ANGRY," but I read on Wikipedia and it said it actually means cigar, both due to its shape and fragility. That's anything but intimidating, even Betty scares me more than that. Evolution just really gave the G4M the worst names...
-Avro Lancaster: Surprisingly, the Lancaster is named not after a place, but a city. At first it doesn't make sense, but I guess it does since it would be a symbol for their country.
-C-47 Skytrain/Dakota: Both make sense, and can go either way; one way is Skytrain, which makes sense since it transported large amounts of people via air, essentially making it a train in the sky, and when flying in formation, its fellow C-47s could be considered the train cars. Meanwhile, Dakota was inspired by the acronym DACoTa, which meant Douglas Aircraft Company Transport Aircraft, but it's also likely Dakota comes from the actual state of Dakota (North and South), which would also make sense since the C-47 is an aircraft of American origin.

Like, an actual person

-B-25 Mitchell: As it would turn out, the B-25 is the only plane to be officially named after a person, at least in the military.

A freaking concept

A6M Zero: Although the A6M has MANY names (just look on Wikipedia), Zero has stuck the most, making the A6M the only plane named after a freaking concept.