'Just another bug hunt...'

My players have encountered a growing list of biological contacts that I myself have been fairly unable to pin down in my head, appearance-wise, and thus every description I give my players has been far too vague for my taste. If someone could take a stab at getting them down on paper, I can lay to rest my own horribly amorphous image of them before it evolves yet again. A list. Green Spiders: much like the knobby white spider of Dagobah, these man-sized arthropods bear a dozen strong, razor-sharp segmented appendages about a vertically-oriented cylindrical body. They come out of the woods in droves during what the colonists of a sad little planet aptly call 'spider season'. They have an octopus-like beak on their underside, in which can be found a nasty stinger set to deliver a venom cocktail to anything they can pin down. They do not eat or reproduce, and inexplicably die out towards the end of the season (My players have to find out why). They are a sickly pale green with dark flecks on a white underside. Red Spiders: these spiders are lower to the ground, although more massive. Something between a millipede and an ant, they have a truncated forward end, presumably a mouth, low to the ground and surrounded by fine maxillae and bearing several compound eyes on either side. Their midsection follows suit, except much larger; almost identical to a few segments of millipede, but their posterior section turns up away from the ground and houses a large fluid sac. They are rust red for the most part, with flecks and bands ranging from pink to salmon. Their environment consists of four key elements I'd like to see a brave soul illustrate as well. Tamboo stalks (basically leafless bamboo), Brell (three-meter tall brown/grey mushrooms, albeit with long strands of multi-colored 'hair' extending from the gills nearly to the ground), and brain-shaped patches of a toxic, blood-red bioluminescent moss lovingly called 'Blush of Death' by the natives. I know it technically falls outside of the 'three characters' request limit, as it's two creatures and three plants, but I would love to show my players all the elements together so they can feel more immersed. This story arc has been my finest to date, incidentally, and I've got all my players guessing at what the CSA is up to on this planet. Thank you for reading, and I'd be more than grateful if some brave soul could lay to rest the poor tortured creatures that endlessly (and likely painfully) mutate in my imagination.