"Ok, you're telling me that these killed the earth with a targeted apocalyptic meteor shower?!"
These were small, black, armour plated creatures not unlike a cross between a monkey and a lizard. The long prehensile tail ended in a sharp barb and a hook, and the feet were cylindrical, with three claws placed evenly around each one, capable of gripping onto whatever surface was below the foot. The head was elongated, with 4 eyes arranged on the head like a triangle topped with a spire. Below these were two orifices, presumably the nostrils, although no nose-like structure was visible on the flat face. At the bottom, a mouth full of fangs gave the creature a ravening appearance.
The nervous voice of the xeno-biologist piped up in response.
"Yes, err.... they have a highly developed cerebral cortex made of an unknown substance, which has properties similar t that of superconductors, granting it stupefying intelligence for such a small creature. We'd never have predicted anything like this unless we'd had this specimen."
"And just how did you get it?"
"One of our scouting teams shot it whilst they were trying to recover you. But this creature has the capability and the ingenuity to escape from Earth, but how, I have no idea."