Captain Underpants is a 13-book series with 13 primary works first released in 1997 with contributions by Dav Pilkey.
1997 • 35 Readers • 127 pages • 3.4
1999 • 21 Readers • 144 pages • 3.3
2000 • 15 Readers • 160 pages • 3.3
2001 • 13 Readers • 176 pages • 3.7
2003 • 9 Readers • 176 pages • 4.2
2003 • 10 Readers • 176 pages • 4
2006 • 8 Readers • 176 pages • 3.7
2012 • 4 Readers • 304 pages • 4.5
2013 • 4 Readers • 224 pages • 4
2014 • 1 Reader • 2