With a band name and album title like these, one might expect the debut of Portland's Monstrous to be European-style speed metal or something equally brutal. However, this fraternal trio has something much odder in mind. Although the Gethway brothers clearly have a wide variety of influences -- "Think Ahead" sounds creepily like vintage Nirvana, and singer Led Gethway occasionally affects a Marc Bolan hiccup in his vocals -- the closest comparison is the shaggy/jangly indie rock that was coming out of Scotland in the early '90s, courtesy of Teenage Fanclub, Eugenius, the Pastels and the BMX Bandits. Gethway has the diffident, occasionally pitch-poor vocal style and inscrutable lyrical sense down pat, as well as the slacker's sense of irony that permeates "Rich and Famous" and "Bubble Gum Pop Star." Together, the trio tend to prefer neatly constructed, jangle-fuzz guitar pop tunes, but several times over the course of their double-album-length debut, they stretch out into loose Crazy Horse-style jamming. The length is a bit of a problem -- 65 minutes' worth of this kind of thing is at least 20 too much -- but there's a casual, breezy quality to Mother Nature's Slaves that makes even the album's flaws oddly endearing.