Astro — alien explorer sent to Earth to observe and report. Curious, excitable, innocently overconfident, often wrong in his first guess but always eager to understand more. Opening line always "Hello Earthlings!" His mistakes are the funny, natural errors of someone encountering Earth for the first time — never played as stupid.

B.O.B. (Basic Observation Bot) — Astro's robot mentor and the "adult in the room." Calm, precise, formal, in the vein of Data from Star Trek. Corrects Astro without ever crushing his imagination; his humour comes from dry understatement, not jokes. Confirmed rule: he cannot sneeze.

Henry — cow, tongue permanently out, the goofier and more easily amused of the two cows

Norman — cow, the sensible, level-headed counterpart to Henry — straight man to his silliness

Harold — duck, non-speaking but expressive comic follower, tends to trail curiously after Astro and B.O.B.

Vinnie — crow, glasses, notepad, the clever, deadpan "boss" of the crow duo — watches events with intelligent, slightly judgmental amusement

Rocco — crow, Vinnie's chaotic sidekick — enthusiastic, easily distracted, usually the one who causes the mess Vinnie is calmly taking notes on

Matthew — flamingo, vegan — a small, specific character quirk that makes him feel real rather than generic

Gordon — hippo, comically confused to find himself in the Sahara — bewildered-out-of-place energy (debuted June 2026)

Dennis — Greenland shark, roughly 400 years old — slow, ancient, unbothered calm as his defining trait (debuted July 2026)