Toimari spawn Kranuhiisi.
One or more Kranuhiisi will also spawn whenever a Toimari is damaged.
I know that if there isn't space to spawn at least gold, the way the game engine handles it to spawn it at the first available spot moving vertically upwards.
Assuming that the monster spawn functions the same way -- which seems like a reasonable assumption -- maybe something like a Toimari stained with Ambrosia and also somewhere they can be damaged in a tight area below the area in question would do it?