Alexander Deyanov (Bulgarian: Александър Деянов), known as SkilleR (formerly PEN-15), is a beatboxer from Sofia, the capital of Bulgaria.

[1] He has been on stage in countries like Japan, England, Germany, Russia, Italy, Austria, Switzerland, the Czech Republic, Romania, Serbia, Slovakia, Vatican City, Greece and many others.

SkilleR takes his beatboxing beyond the traditional big band jazz and ska influences into a much wider range of contemporary styles.

'[2] The ability to express himself in a different way gives him the opportunity to explore the art with various projects and has made him attractive for one of the most successful companies in the country—Nestlé Bulgaria.

He has been on stage with various international artist like Shaggy, Lumidee, Outlandish, Jaba, N.O.H.A., Stereo MCs, Transglobal Underground, Thursday by Six, The Jettisons, Foreign Beggars, Karma Rocket, The Society Kids, Chemical Toilet, The Pecan Sandies, The Animaniacs, Lisa Gerrard and many others.