There are a few characters missing, as I never bothered to give them daemons, or they appeared later than my headcanon went. I have my OCs, though, and the Trio verse muses.
Sometime soon I'll do something contructive with all this headcanon, and write a proper story. Probably.
Tzophiya (Hebrew name meaning 'watchful') (Zoh-FY-ah)
Grey Lourie aka African Go-Away-Bird
Grey Louries are awesome birds. Their cry actually sounds like 'go away', which is what initially drew me to it, but they also hang around near packs of animals, and wait until a hunter is just about to strike, then cry 'go-away' and alert the animals, thwarting the hunters. They also are apparently prone to being silent at home in their nests, and very vocal in public.
Subira (Swahili name meaning 'patience') (Su-BEER-ah)
Mongooses are small, but very fierce, which is why I choose one for John. They also live in small groups, but hunt together (like an army) and look after their old and sick (like a doctor). Plus they are adorable.
Leala (Breton name meaning 'loyal') (Le-ALL-ah)
I wanted a dog for Lestrade, because I thought he's sort of a servant to the law, and in the HDM 'verse, all servants have dogs. I choose the otterhound because it's a bit rare, and because of the description of it on Wiki: "a Bulldog's courage, a Newfoundland's strength in water, a Pointer's nose, a Retriever's sagacity, the stamina of a Foxhound, the patience of a Beagle, and the intelligence of a Collie"
Carwyn (Welsh name meaning 'caring') (CAR-win)
This is based solely on Sherlock's line about how England would fall if Mrs Hudson left Baker Street, which is what is said about the ravens in the Tower of London. Also, ravens have very affectionate but antagonistic relationships with their families.
Hisoka (Japanese name meaning 'secretive') (Hiz-OH-ka)
I choose the Pallas's cat because I wanted a cat for Mycroft, but not anything common. I also wanted it small enough to curl around his shoulders, because that's how I picture his daemon, draped across him lazily and glaring at you. Plus, Pallas's cats make the best bitch faces.
Duinn (the island where the dead go in Celtic mythology to wait to begin their journey to the afterlife) (DWIN)
Japanese Flying Squirrel
Japanese flying squirrels look like they've been animated by Disney, and I basically choose them based on that. They are adorable, and always look quite cheerful and sweet, and nervous. I pictured Molly having a daemon with a tail that swish-swished back and forth all the time.
Quenell (an old English name meaning 'battle woman') (Quah-NELL)
Superb Bird of Paradise
I wanted something showy for Irene, and a bird, to mirror Sherlock's daemon. Superb Birds of Paradise have insane mating feathers, and do a little dance to try and seduce their mates, which I thought suited Irene's habit of putting on her battle dress and challenging consulting detectives.
Persepnei (Etruscan form of Persephone, the goddess of the underworld in Greek myths) (Pair-SEP-nee)
Death's Head Moth
Aside from having a skull on its back, I liked the idea of Jim having something flighty and 'changeable'.
Effimia (a Greek name meaning 'Good thoughts') (eff-ah-MI-ah)
Degus are very intelligent, and are good problem solvers. They also are known to make tools to help solve problems, which reminded me of Q's inventerly ways.
Larisa (from the Spanish 'la risa' meaning 'laugh' and Russian Larissa meaning 'citadel') (La-REE-sa)
Meerkats are friendly little things, that live all together in happy group, and wander around being adorable all the time. They tend to smile, which Alec does a lot, and they, unlike a lot of other animals, actively teach their young skills, instead of letting them pick them up by observation.
Jabir (an Arabic name meaning 'comfort') (Ja-BEER)
Canada geese mate for life, and if one of them gets sick or wounded, they stay on the ground and care for them until they're well. I wanted something doctorly for Sarah, and I also liked the idea of her daemon being quite a bit bigger than John's daemon.
Apellon (the old form of Apollo, who was a God of music, art, poetry, and knowledge) (APP-el-on)
A strawberry poison dart frog (blue jeans variation)
I googled 'colourful animals' for Dora, and this one appealed to me the most. I thought a frog suited her energy and tendency to hop from one task to another, and it amused me to think of her daemon being very small in comparison to her sons' daemons, but totally able to keep them under control. Also, strawberry dart frogs are the best parents amongst the amphibian world, with the females lovingly looking after their children and being social amongst themselves, while the males are very anti-social, but fiercely protective. Which sounded like Dora and Siger in a nutshell.
Hermia (the feminine of Hermes, the Greek messenger of the gods, and the god of language and trickery) (HAIR-mee-ah)
I looked for animals that used complex language, since Siger loves to muck about with words, and I found out that mynahs are able to learn to speak better than any other birds. They're also related to the corvids, which are the most intelligent bird species. Also, they look very grumpy almost constantly.