reading the counter strike wikia, I found an interesting topic, Secrets/Easter Egg the wikia has detailed information about easter eggs from official maps, however, it has little information about custom maps. I thought it would be fun to share easter eggs from custom maps found by ourselves
for example, in fy_iceworld2k, below the map, there is a small room with a signature
Awesome topic! I also built in most of my maps a hidden "CS" (the initials of my real world name) made of brushes. I don't want to post them here for myself, but let you try to find them. Some are accessible while playing, but well hidden - others only in freelook mode.
Try to find them in cs_huehnerklau de_lidl cs_colarausch as_die_bart_die! cs_oemska cs_gabba de_castordepot_v2 hoellische_nachbarn de_wanted de_roaches de_train_assault csde_pirateship cs_brokkoli
God, there are so many that I've come across just uploading the stuff I've found over the past few months. NIPPER's logo is so well known in the mapping community that it's more a staple than an Easter egg, but Xavier's logo can also be found in pretty neat places on his maps.