The Blastcap is a mushroom-like fungus which is native to the planet Tallon IV.
Blastcaps can grow alone, but tend to grow in small clusters. When approached, they will make a rustling noise and shake violently. Upon contact, or when sufficiently damaged, they will violently explode, destroying itself and anything in the immediate vicinity and releasing a cloud of noxious gas.
The spores of the Blastcap can survive in outer space, and have propagated throughout the galaxy by means of traveling on interstellar solar winds. This has resulted in the species traveling as far as the Alimbic Cluster, where it has colonized Alinos and Arcterra. The Blastcaps found on Arcterra are simpler in structure, lacking the tendrils of their Tallonian counterparts and having a red spot in the center of their caps. However, the lingering cloud left by these Blastcaps is more dangerous, and capable of even harming armored individuals.
In Metroid Prime, Blastcaps can be found in these rooms: Tallon Canyon, Watery Hall, Waterfall Cavern, Meditation Fountain, Ruined Gallery, Gathering Hall, Watery Hall Access and Transport Tunnel C. In Hunters, Blastcaps are located in High Ground, Alimbic Gardens, Crash Site and Frost Labyrinth.
Volatile chemicals within this weed's toxic fungal cap may explode if agitated.
The poisonous flesh of the Blastcap helps keep it from being eaten. It also detonates its fungal cap when it senses even slight contact.
- A similar species of mushroom known as "Blaxcaps" appears in the first Pikmin game during the final battle with the Emperor Bulblax.
- An unused variant exists in the data of Prime.