Sergeant Axel "Guns" Enroses is a terran soldier who served on a jungle planet at some point, although seemed to be rather familiar with such an environment, suggesting that he'd served on others beforehand. He delivered a speech to new recruits concerning it;
Welcome to the jungle... it gets worse here everyday. You learn to live like an animal in the jungle where we play and if you’ve got a hunger for what you see, you'll take it -- eventually. You can have anything you want, but you better not take it from me...
2000-05-19, Tropical Fever. StarCraft Compendium Map Archives. Accessed on 2007-11-13.