The Strange Old Man can be found digging in the Barrows mounds. As his title suggests, he is a very peculiar individual with an obsession for digging, often saying strange things. During The Temple at Senntisten, he assists in recovering the icon guarded by the six brothers. He also sent a scroll containing The Fall of Six to Reldo, found in the Lores and Histories section. The crumbling tome used to occasionally be received when he was talked to but it is now on a table north of Barrows near the entrance. He has recently put spades to the Barrows mounds, which can be helpful for completing the Barrows minigame.
This article on an NPC has an associated dialogue page. Click here for a transcript of possible conversations with this NPC.
After having completed the quest Spirit of Summer, if a player talks to the Strange Old Man whilst wearing Jennica's ring then they will have a conversation with him, where he laments about Jennica, and begins talking about digging.
If the player stands in front of the Strange Old Man in the direction he is trying to walk he will constantly perform his digging action on the player until he disappears and is reset on his normal path of movement.
Contrary to his obsession for digging he is not actually digging; he is tilling, which is the act of softening soil.