Given the Red Oak's destructive nature mentioned earlier in this entry:
http://www.newgrounds.com/art/view/thepsychosheep/rooted-spawn

It was no surprise that the kingdoms still unaffected by the ravenous plague of destruction would immediately act and devise a counter attack to slay the being.The first to participate in this quest was of course the currently largest ruling and spread sovereign nation of humans.The king would send out armies of his bravest knights to seek out and destroy The Red Oak's branches until they reach the very heart of the beast and kill it once and for all.The very best equipment had been forged,the biggest ceremony had been held and the plan was put in action.Anxious for their triumphant return,the king and his people had high hopes and prayed to every possible god in their pantheon for the safety of their noble knights.But worrying signs had started to appear as weeks passed since the campaign started,soon turning into months and not a single report came back to describe the situation.People started to loose hope while the king and his men were shocked at how an entire legion of troops would suddenly disappear without a trace.It was only when a small village not far from the capital was attacked by the resurrected rooted army of the Oak.A squad was send immediately to fend off the attack and save whatever they can from the village.This prove that not only the King's campaign had failed to stop the Oak,but that it had managed to spread it's roots even deeper into the land and it will most likely continue to grow.People who managed to escape from the now ruined village reported of the kingdom's knights walking along the rooted spawn,encased in thick branches and killing off villagers.The King's army that was sent to vanquish the Oak,had now become it's own legion.