If you hand Ulgrim the hangover elixir you find in a chest downstairs, he says:

Ulgrim the Unpleasant tells you, "No thanks, I never get hangovers. You keep it."

However, he did not give it back.

If you hand him the ring you find in the locked chest:

You give Ulgrim the Unpleasant Ring.
Ulgrim the Unpleasant tells you, "Aha! Another ring for my collection."
Ulgrim the Unpleasant tells you, "Wait, This ring looks familiar."
Ulgrim the Unpleasant tells you, "This is MY RING!!!"
Ulgrim the Unpleasant tells you, "You stoles it!!!"
Ulgrim the Unpleasant tells you, "Get out of my house you nasty thief!!!"