SOOG virtual instrument is a free sound bank for Reaktor, by Icebreaker Audio.
S.O.O.G. (Sub Octave Oscillator Generator) is an analogue style octaver effect for Reaktor 5.8+.
The effect produces a fuzzy version of the input signal, by generating a modulated square wave one octave below the tracked pitch. This fuzzy octave can then be filtered to smooth out the tone, or to create synth style sounds.
The effect works best on monophonic instruments with strong fundamental frequencies like bass guitars or clear vocals.
http://www.icebreaker-audio.com/