I can't claim to know him either, but I believe he may be the player who has appeared on more Topps Traded and Update cards than any other. I make that claim pretty lightly and without a lot of research.
I recently pulled his 2012 Topps Update card from a repack. As I was cataloging it I noticed that I had 9 cards of his and that most of them were either Topps Traded or Topps Update. We all know players who move around a lot. These tend to be marginal players who didn't appear on a lot of cards.
A former Phillie, Terry Mulholland, is a guy with a 20-year career who changed teams about 13 times between 1986 and 2006. Yet (according to Beckett.com) he only appeared on 3 Topps Traded cards. Chad had an 11-year career between 2003 and 2013 and played for 9 different teams. He appeared on 6 Topps Traded or Topps Update cards. I've got 5 of them.
2004 Topps Traded #106
In December 2004 he was traded to the Blue Jays and spent 2005 with the Jays splitting time between the majors and minors. All his 2005 cards (pretty much all Donruss sets and Topps Total) have him as a Devil Ray.
In December 2005 he was traded to the A's. He spent 2006 and 2007 with the A's. 2007 was his best year when he was 11-13 in 34 starts with an ERA of 4.42. He doesn't appear on any cards in 2006 except some minor league issues.
2007 Topps Update #126
This is the one I'm missing. His 2007 Traded card shows him with the A's.
2008 Topps Update Gold Border #85
2009 Topps Update #208
In March 2010 he was released by the Yankees and picked up again by the A's. The A's released him in May and the Yankees resigned him. He was a combined 1-4 with a 5.65 ERA in 46 appearances, but no starts.
He was a free agent in November 2010 and the Nationals signed him in December 2010. He was 1-1 with the Nationals before being released in July. The Blue Jays picked him up again in August but only pitched in the minors. He was a free agent again in November 2011.
He appeared on no baseball cards in 2010 and 2011.
2012 Topps Update #252
2013 Topps Update #86
The Phillies signed him in January 2014 but released him in February when he failed a physical. He did not appear on any 2014 cards and did not play for a minor league team in 2014 so it appears he is out of baseball.
In his 11-year career Gaudin was 45-44 with 87 starts and 344 relief appearances. He had 2 saves and a career ERA of 4.44. His career salary was $7.4 million. A well-travelled career but I think any pitcher who can leave after 11 years with a winning record has done a good job.