If not picked, it will glow at Dusk and Night, providing enough light to ward off Charlie. While glowing it also has a Sanity aura.
The sprout can be permanently destroyed with a hammer for two Limestone and a Brainy Matter if it is not already picked.
The Brainy Sprout’s sanity aura has a very short range requiring the player to sail directly adjacent to it in order to benefit from the bonus sanity. If planning to build a Sea Yard nearby, it would need to be very close to the sprout for its repair range to overlap with the sanity aura.
It is useful to store Brainy Matter in a Bundling Wrap to prevent it from spoiling.
Their brain shape and the fact that they spawn in the reef biome could be a reference to brain coral (Diploria labyrinthiformis).