The mechanic
The Geode Broodmother has the biggest raw health pool of the whole roster and no armor. Unlike the threshold bosses, she does not wait to be hurt to spawn adds: she does it on a clock the entire time she is alive.
Every 6 seconds she lays 1 geodeling, a lightly armored add, up to a cap of 8 alive at once. The longer she stays alive, the more geodelings pile onto the path, which flips the usual rule on its head: killing her faster means fewer adds, not more.
When she finally dies her geode bursts into 4 geodelings at once as a parting shot.
How teams beat it
Race her down. Because the adds come from a timer rather than damage thresholds, every second she lives is another geodeling, so pour your heaviest sustained damage into the queen herself and clear the trickle of geodelings as they come.
Like every boss, it fights inside the showdown rules: kill it and it respawns about twenty percent stronger on the rival's lane, let it leak and it crosses unescalated. The full showdown rules are in How a match works.
