Niko Nirvi (or NNirvi, as he's most often known) is an editor and columnist in Pelit magazine. He seems to mostly review strategy games, RPGs and FPSes.
His first game review was for Zoids in MikroBitti 6/1986 (which is why people call him "older than dinosaurs"), and since then he has written a lot of game reviews - mostly in interesting and fun way. Previously, he wrote for MikroBitti, but moved later to Pelit.
If you want to laugh, read his reviews of really bad games. He's also good at spotting cliches and bad things in general that plague the modern games, and these are generally the most common topic of his columns.
Oh, and he never, ever has shown his face in Pelit or MikroBitti. It's a great mystery. (Update 2002-02-17: NNirvi has been spotted on TV recently on report about Pelit Awards Gala...)
For Pelit subscribers, all of his columns and game reviews can be found from http://www.pelit.fi/.
Pelit also now includes this in their gaming dictionary: "Nirvi Gambit: n. A stupid move in the end of a multi-player game that turns your certain victory into certain defeat."