Stilgar

Stilgar is one of the seven Galastropods in Astroneer.

Source
Stilgar is rewarded by completing the G. calidor: Recovery mission, after providing an Empty Terrarium with Soil, Copper, and a Wheezeweed seed for the G. calidor: Terrarium mission.

Uses
Stilgar provides oxygen to the player, similar to a Portable Oxygenator, and also to nearby tethers for 10 minutes when fed a seed. Feeding Stilgar a Mutant Attactus Seed increases the buff to 30 minutes.

Trivia

 * The name Stilgar is likely a reference to Frank Herbert's Dune series. In these books, Stilgar is a major secondary character and native to the barren desert planet Arrakis.
 * This is furthered by the quotes "THE AIR MUST FLOW!" likely being a reference to "the spice must flow"
 * The pun of the galastropod being a "spicy" addition further contributes, as well.

Galastropoda calidor // Stilgar
"A resilient companion who lets you breathe easily on any adventure when well fed. Stilgar is a spicy addition to any backpack: THE AIR MUST FLOW!"