Giant canyon isopods (Porcellio dilatatus) are HUGE isopods native to Europe. They're pretty plain (albeit prehistoric)-looking and spend most of their time entirely underground. As you may be able to infer, giant canyon isopods aren't too popular as display critters or pets.
What giant canyon isopods lack in beauty, they make up for in brawn. Between their girthy size and sub-terranean lifestyle, they're usually capable of staying alive while sharing an enclosure with small lizards or frogs. Furthermore, their large size and tunneling habits allow them to aerate your bio-active substrate mixture like no other isopod.
Giant canyon isopods are one of the few options suitable for arid enclosures. Still, they'll also do fine in humid tropical set-ups, and they truly thrive in temperate environments - they evolved to live in Europe, after all.
These giant arthropods specialize in eating decaying leaf litter, especially Alder tree leaves. They also love lettuce and other leafy greens. Be sure you've got a healthy supply of food before taking on a colony of giant canyon isopods - they have huge appetites to nourish their huge bodies. You'll be amazed at how fast these "bugs" can make organic matter disappear!