Theo Paphitis was the first investor to appear on the British show Dragons' Den after the original series.
Paphitis joined the panel in series 2, replacing Doug Richard. He was already known in British retail and became associated with businesses including Ryman, Robert Dyas and Boux Avenue. His retail expertise shaped many of his contributions when entrepreneurs presented consumer products.
This question concerns the first-series-to-second-series panel change, not the later arrival of Deborah Meaden. Paphitis became one of the programme's most recognisable investors and remained on the show for several series before leaving. His appearances helped establish the rotating-panel tradition that later became normal for Dragons' Den.