Pigtronix Octavia arrived last week. Aimed at guitarists, but I like it a lot on bass (not least its compact form factor). It has a brighter, crisper fuzz than my Red Ripper which I suspect could cut through the mix very well, and sports a capable LPF for dialling back treble / producing a more vintage tone. It's definitely not an octave-up pedal in the way we normally think of one, though!