Humans. They seem a lot like you in many ways... Things there are no words for, impressions. Your love for each other, your complex hierarchies, the creation of vast quantities of tools and strange art... I was much younger and less understanding when I last saw humans. I do not know as much about them as I would like and I do not dare return to Oldhome in case they have devised some way to follow my trail to Newhome. When humans first came, they flew in great starships like mine. The ships deposited colonists and began clearing land and killing Draak. They saw Draak as beasts and pests, something dangerous to be exterminated, and began this project with guns.
When the Draak rose up to fight back in the first war, these lesser ships were mostly destroyed and we began hunting the colonists to eliminate their threat. Then, greater ships came - larger vessels, and in vast numbers. They used weapons that we still do not understand, that seemed to tear apart space itself. A famous Draak invented an incredibly destructive technique or tool to fight back with. It could burn entire forests to cinders in seconds. Very little is known about the course of the first war from that time on and many, many things were destroyed. Only Draak living secretly and remotely escaped destruction, but the human ships left and never returned again, leaving their colonists behind, unable to sustain their technology.
And centuries later, they had pried themselves out of their suffering with tools of bone and stone, then bronze, then steel, and multiplied to tens of millions. That was when we knew they would end us and the second war began. Humans. Aggressive and expansionist.
The Surveyor Orbs. I discovered and analyzed reflective spheres of machinery that were travelling methodically over the planet. They did not respond to any attempt at communication, but I eventually determined that they were searching for some natural resource and sending their results to a distant controller. I was not able to tell what the resource was, or where the controller was, even when I began intercepting their transmissions. Eventually they self-destructed. Surveyors. Confusing but benign.
The Collectors. The aliens I adapted the white projection from sent robots. They busied themselves collecting samples of every species of life on the planet, non-violently. They would 'taste' plant leaves, take small samples of blood or other things from animals, never killing. They also took on the forms of beautiful versions of female humans and Draak and tried to get males to have sex with them. I believe they wished to create new humans and Draak in some far-away place. When I refused and demanded an explanation, the robot seemed to be replaced by an alien who conversed with me, but they refused to explain themselves, only saying that they meant no harm and that I would not understand. Collectors. Confusing and worrying, but ultimately benign.
The Miniscs. A race of insect-sized bodies which formed a gestalt mind capable of complex reasoning and intricate tasks. They landed in a meteorite on Newhome and expanded quietly, building a glittering city in miniature, until the one who is now called Guardian of the Great Green heard their minds singing. They claimed they were sent on a sacred mission, and asked to trade - the Guardian would collect samples of local species and they would create Treasure for her. She accepted, and the Miniscs lived peacefully without reproducing any further. I do not know what ultimately became of them or what their purpose was. Miniscs. Confusing but benign.
The Blueblight. An extremely effective and aggressive parasitic fungus-like species. Even a few cells can cause an infection that kills in days or weeks. Full-grown Blueblight infections have visible minds in the song, but the individual spores do not, making them extremely dangerous. They appear alien and almost mechanical in the song, growing, developing, and releasing spores in ways that seem designed rather than evolved. It would consume many, many kinds of things if left to spread, though it was less good at overcoming plants than animals. I don't know where it came from. Possible rogue bioweapon.
And lastly... I am not actually sure it was an alien or a disease... But some humans became 'infected' with a new pattern of thoughts and actions that significantly altered their personalities, caused them to want to live away from uninfected humans, and caused them to want to kidnap other humans and torture them. Sometimes the tortured humans would become 'infected' as well, or they would die. It was... Disturbing. The humans eventually killed them all.