This nice letter from Nigeria was sent by Ahmed, thanks! It was posted in Ikoyi on August 6 and arrived on August 12, 2014.
The stamp is part of a set, which commemorates the Cross River Gorilla (Gorilla gorilla diehli). The set was issued on March 26, 2008.
I am Florian, a 36-year-old cover collector from Austria. I am trying to receive at least one cover from every country of the world. If your country is on the list of missing countries, please send me a cover, I am replying with a nice-stamped one from Austria!