Try to defeat the hydra!

The hydra currently has: segments, heads, and depth . Hercules has cut heads so far.

Click on a head to chop it off.

• When a normal neck segment () is cut off, the grandfather node of the severed head, if any, can afterward grow back as many copies as the hydra wishes of the entire subtree from which the head was cut off (i.e., the father node of the severed head and all its descendants).
• When a dire neck segment () is cut off, the father node of the severed head can afterward grow back a copy of the entire subtree back from and including the last normal (i.e., non-dire) segment in its ancestors, recursively as deep as the hydra wishes.

Nodes which have just grown back are shown slightly blueish ().

Restart with a new hydra.

Undo previous move (only one level of undo).

Start auto play or stop auto play.