Not one of its hundred heads was safely cut off without its neck generating two more … with branching snake-heads, that grew from their own destruction, thriving on evil.”

Ovid Metamorphoses.

A hydra launches multiple copies of tiny bombers / clears. There are several early examples, but the first successful hydra didn't appear until December 1989 when Stefan Hänßgen won the German Branch Section Core War Tournament.

Example Hydræ

Abomination is a continuous hydra which boots multiple tiny bombers.

return of the living dead uses a simple launch to boot multiple clears.

Paratroops v2.1 uses a loop to launch multiple clears.

Hydra and Night of the Living Dead use a binary launch to boot multiple clears.

Nemesis, Torment and Cloudburst pair a continuous hydra with a paper/imp.

Leviathan uses a binary launch to boot multiple tiny bombers.

Lithobolia binary launches multiple tiny bombers and a paper/imp.

Hordes of Microwarriors is a continuous hydra which boots multiple clears.