I've got 13,208 Cubs cards from 102 different brands listed on a spreadsheet. A random number generator picked five cards, one each from the past several decades.
1900s - 1970s: Kelloggs 1979 #47 Rick Reuschel Big Daddy! Reuschel led the 1979 Cubs in starts (36), wins (18), and innings (239). He went 7-0 in August and was the NL Player of the Month.
1980s: 1989 Fleer #643 Major League Prospects Mike Capel and Drew Hall Both of these pictures are at Wrigley Field, so these guys already had some big league time when Fleer decided to put them on this prospects card. Capel spent the entire 1989 season in AAA working out of the bullpen. The Cubs granted him free agency after the season. Hall was hardly a prospect in 1989, have pitched for the Cubs in three different seasons, 45 games. He was traded to the Rangers over the winter of '88-'89 as part of the Mitch Williams / Rafael Palmeiro trade.
1990s: 1997 Fleer #275 Luis Gonzalez Looks like Gonzales is battling the sun. Gonzalez didn't play for Cubs in 1997. He became a free agent after the 1996 season and went back to the Astros, the organization that originally drafted him and traded him to the Cubs.
2000s: 2002 Fleer #433 Alex Gonzalez The RNG likes Fleer cards and players named Gonzalez today! This Gonzalez came to the Cubs via a trade with the Blue Jays. He was the Cubs everyday shortstop in 2002 and hit 18 home runs while batting .248. He made a whopping 21 errors, but his most infamous would be a year later in game 6.
2010s: 2103 Bowman Prospects #8 Tayler Scott The fifth round draft pick in the 2011 draft has been inching his way up the Cubs chain, moving up one step each year and spending the entire season with that team. In 2014 he was with the High A Daytona Cubs. He started 26 games and recorded a record of 8-8.