[ericd]

Or perhaps a missile full of drones, similar to those bombs with lots of guided submunitions.

[aerostable_slug]

Tomahawk TLAM/D carries 166 submunitions in 24 canisters. There's no reason those submunitions need to be dumb — or stationary for that matter.

[racnid]

I can't seem to find any reference for what actual submunitions a Tomahawk carries but conventional cluster munitions can already be smart:

https://en.wikipedia.org/wiki/CBU-97_Sensor_Fuzed_Weapon

[MikeDelta]

Indeed, cheap and available in massive amounts also makes very dangerous.

Funny that we see this in various computer games, ships with drone bays. What you mention would be a drone missile perhaps?