Ballistic Squid
This species of alien mollusk (about the size and general shape of the largest Terran giant Pacific octopus) shows obvious signs of genetic tampering; it absolutely should, considering that it can launch itself out of the water and travel about a hundred feet up before gravity takes control again. This is not a survival mechanism; Ballistic Squid can survive the experience if it lands in the water again, but if it hits anything metal the Squid’s body pulps itself. More genetic engineering, probably.
The best guess from the xenobiologists is that Ballistic Squid were engineered to be biological weapons; once pulped, the Squid’s flesh transforms itself into a complex chemical stew that rapidly disperses into the atmosphere. Fortunately, the chemical is harmless to most of the ‘cousin’ species in this arm of the Galaxy, including humanity; whoever designed the Ballistic Squid wasn’t descended from the same panspermia bacteria as the rest of the currently known space-going species. It certainly smells atrocious, but that’s about it.
Ballistic Squid are annoyingly clever about escaping their containers (while being abjectly stupid about everything else), can breed successfully if slowly from a small population (more genetic engineering), and can usually find something to eat in various oceans of various Earthlike worlds. They also tend to react badly to sudden loud noises and impacts in the water, typically by activating their launch reflex. All of which means that any spaceport that uses water for takeoffs or landings will eventually have a temporary Ballistic Squid problem; ‘temporary’ because the Squid colony typically resolves the situation itself by smashing against spaceships as they take off and land. Generally, this does not cause crashes; the ships are usually well armored and stable enough to shrug off the ‘attack.’ But it can be extremely startling to have a giant alien octopus smear itself all over your forward canopy.
Also, disgusting.