So I'm re-writing my prologue where we first meet the big bad demon-like nasties that are the main enemy of my MC and her country. I also have to introduce the good guys mounts, which are a mix of fantasy beasts like hellhound, hippogriff, a saber-tooth like cat and a bear-type. How do you work in your descriptions without stopping all the action to get the full picture? I have bits like these: "His hellhound, Garmr, snorted and a wisp of smoke drifted out of his nostrils. Liam leaned over the saddle and patted his mount reassuringly." "Garmr was on edge too, the big black, dog-like Beast nearly vibrating with tense energy. " "Jaymes guided his hippogriff, Ghostwings, to the ground. The setting sun illuminated the half-eagle, half-horse from behind, making the tips of the beast’s feathered wings appear to glow." "Two Riders approached, one on a big bear that looked like a cross between a grizzly and a polar bear, one on a huge saber-toothed cat. Oh, good, Liam thought, they ride an Ursai and a Friesencat, those are powerful Beasts that can help us with that sarangay. He thought back to what they had been taught in their classes on the Drorm. Half man, half bull, sarangay were huge creatures, with thick horns sprouting out the sides of their heads, wickedly clawed hands, and cloven hooves the size of dinner platters. He did not want to take on one of them by himself, for surely Jaymes would have to deal with the smaller Drorm, the raskguthan. Just as nasty as the sarangay in its own way, but smaller, they resembled a rat crossed with a scorpion, with a shelled underbelly and a poisoned stinger on the end of their long naked tails." Does sprinkling it in like that work? Do you think the reader is getting a good enough mental pic of these creatures? Because next come the battle scene, and I don't want to have to pause and describe my nasties (the Drorm) or my good Beasts too much and bog down the action. Any tips for working in descriptions so it gives a clear picture but doesn't slow down the scene?
For me, little bits like this one work. Big bits like this one don't. That comes across like the author wanting to showcase their worldbuilding. Some people like that kind of thing, but it's not to my taste. Personally I go for a less-is-more approach with stuff like this. I don't think it matters if my reader doesn't have the exact same mental image I have, as long as they've got the important details. For instance, does it matter if your readers know that a hippogriff is half-eagle, half-horse? The important parts, I imagine, are that it's big enough to take a rider and can fly. Throw in a bit of vaguely war-horsey behaviour (Rearing up? Clopping hooves?) and mention the beak and you've probably done enough. Equally I don't think people need a detailed image of a raskguthan - you can mention dodging a stinging tail as part of your action scene and it'll slot in fine. Obv, YMMV. If you're set on giving a more detailed picture, I'd try and keep it tied to memories, experiences and reactions rather than flat half-X half-Y descriptions: You can also try doing it via dialogue rather than in the body text - maybe a more experienced warrior telling a farm boy who's been given a pitchfork and sent to the battle the kind of thing they can expect: Or all of the above. Variety kills boredom. Hope that's some use. Good luck!
Agree with @NigeTheHat about liking the short bits but disliking the longer ones. In general, though, I think you're on the right track containing the descriptions inside dialogue beats and bits of action so long as they're not listed sequentially. I know they're not--you excerpted the relevant parts and had to list them here for reference--but if they appear too closely together it might seem info-dumpy. But then there are times when a well-timed info-dump can work--particularly in fantasy or sci-fi--if gets the explanation of fantastical/speculative things out of the way quickly and effectively. Probably not the case here, as the characters and their pieces are going to be around for the duration.
You might consider focusing a bit less on physical descriptions and more on temperament. Maybe something like "The powerful bat-toad tensed under him. Uh-oh... bad news! A rabbit had crossed the path, now he'd have a time trying to get the beast back on track, unless he let it sate it's ravenous hunger first." Ok, not very good, but I hope it gets the rough idea across. In my example it sounds more like he neglected to feed his mount. But attitude and habits are at least as important as the way something looks.
