While poking around on one of the baseball card forums that I frequent more frequently these days, I found an image of a 1952 Bowman card (#15) of Senators outfielder Sam Mele.
On Mele's right arm is a tattoo. It looks like it might be rose or other flowers; it wouldn't surprise me if there was a banner below with "Mother" or the name of a sweetheart.
I'm guessing this is the earliest card to show a player's ink. On the small black-and-white action photo on Mele's 1954 Topps card, you can also see a dark blob on his right arm, but can't make out any details.
The '52B is the only Mele card I've seen that shows this body art. He appears on Bowman cards from 1949-52, and 1954-55, and on 1951-52 and 1954 Topps cards as a player, and on 1962-67 Topps as manager of the Twins.
Mele appears with neither Topps nor Bowman in 1953. He was traded from the Senators to the White Sox in May, 1952, though you'd think that would have allowed plenty of time for the Bowman photographers and Topps artists to get a picture in his new uniform in time for the next year's cards.
And, while he played the entire 1956 season with the Indians, Mele didn't make the cut for the '56T set, having signed with the Tribe as a free agent just before the season opened.
Another bit of baseball card information I found on Mele concerns his 1954 Red Man card. He can be found depicted with either the White Sox, with whom he ended the 1953 season, or the Orioles, to whom he was traded on Feb. 5, 1954. It looks like the Standard Catalog of Baseball Cards may have the relative values of those two variations transposed. A check on eBay shows 8-10 of the White Sox version available, and none of the Baltimore, yet the Sox card is priced at a 22% premium. Also in 1954, Topps and Bowman differed in their depiction of Mele; Bowman has him with the Sox, Topps with the O's.
Today, of course, tattoos on players' cards in all sports are ubiquitous. That wasn't always the case, though. In the mid-1990s at least one of the card companys was airbrushing tats off player photos.