A mandated Syndicate reward that grants a random level-3 Earth hobby skill — usually something useless.
The Earth Hobby Potion is a reward the Syndicate Government requires be given to every crawler who chose a domestic (Earth) class, per the Indigenous Species Protection Act — a bit of bureaucratic Earth-culture preservation that reads like military busywork. Drinking it (optional, and untradeable) grants a random level-3 skill in a unique Earth hobby the crawler doesn't already have; the odds favor useless results given how many 'boring assholes with inane hobbies' Earth had. Princess Donut got Scutelliphily (a term she found vaguely obscene and useless), while Carl received level-3 Cesta Punta — both baffled by their picks.
A potion vial.
A mandated novelty reward granting random, usually-useless Earth hobby skills.