Space Caterpillars are a species of alien animals similar in appearance to the caterpillars on Earth.
Small, fuzzy, football-sized creatures that Pidge encountered in the Trash Nebula after being ejected from the corrupted wormhole at the end of Season 1. They come in shades of pink, blue, yellow, and green, with tan segmented underbellies and eight tiny stumps for legs. They also have glowing facial markings reminiscent of an Altean.
They seem to have some innate connection to technology, as they realized the Green Lion had recovered from its damage before Pidge herself did.