Ancient Golem

The Ancient Golem is a neutral Minion in League of Legends described in game as "A tough monster that attacks with slow but punishing blows. Slaying this foe greatly increases mana regeneration and reduces cooldowns." ''Imbued by the power of the Nexus, the planet itself rises up to bring forth a protector of its lands. The Stone Golems roam the forests of Summoner's Rift, imbued with the strength of the Nexus and acting against any who disturb the peaceful wake of this isolated battleground.''

Tactical Relevance

 * Due to the high mana regeneration the holder of this buff is able to spam his abilities without caring about his mana. For example Zilean and Sona can use this very well.
 * Shaco can solo the Golem at level 1 when he sets several es before it spawns. This gives an high advantage during the early laning phase.