Blastcaps are a species of mushroom-like flora whose homeplanet has been blurred due to the fact that their spores can survive in space, allowing them to propagate throughout the galaxy as well; however, evidence points to their originating on Tallon IV. They have been notably discovered on Tallon IV, although they can also be found on both the planets Alinos and Arcterra in the Tetra Galaxy, proving that they have not only existed for an extensive period of time but also that they have spread beyond our own galaxy. These spores move between locations by traveling upon the interstellar stellar winds. Both those on Alinos and Tallon IV have large, grey-green caps, while those on Arcterra sport white caps, suggesting them to be an arctic subspecies that may or may not have adapted specifically to that planet.
Blastcaps live in small communal clusters, yet this seems to actually be harmful to their species. Blastcaps are territorial towards other organisms, and when one approaches (how they detect these other organisms is likely due to their tendrils - which extend from the underside of their cap - probably being sensitive to air disturbance) they will shake violently, producing a rustling noise as a form of warning. This is because when disturbed they will violently rupture, spreading a noxious gas. While the explosion is harmful enough to deal damage even to powerful armored combat suits, the gas can be filtered and is not harmful to those wearing sufficient facial apparatuses.
On Tallon IV they have been cataloged as inhabiting both the Tallon Overworld as well as the derelict Chozo Ruins.
- Metroid Prime (First appearance)
- Metroid Prime Hunters