good god... that bug was hard to find... but its fixed! ops:
on some systems using 3dNow optimization, killing the hydra will cause an animation error. :fuzzy:
sorry about that, good news is you did kill the hydra

here is the Patch for it.

For a quick test go to Design mode and type:
"add flatterrain 0 0 -25"
"add hydra"
"slaughter hydra"