Lobo

Lobo was a shaggy-haired tramp living in a cave in the Rocky Mountains near the Zealot compound. He sometimes snuck into the compound and foraged for food in their trash. The evening before Head Shot, he witnessed some "hog-faced" men kidnapping and killing all the Zealots. They had seen him and tried to pursue him, but he escaped. They chased him throughout the next day (prior to Head Shot) and so he escaped back to the compound.

Head Shot
Jack Bauer and Frank Neal were investigating the Zealot compound and saw Lobo there. He explained to them what he saw, and Jack offered to give him a hot meal if he would go to their office and write down what he said. Lobo agreed, but was shot dead by his pursuers before the conversation could continue.