Hound no longer exists as a creature type in Magic, and any card with hound written in its typeline has received errata to be a dog instead
Exile Travel Through Caradhras
Kail: ...alright
According to the lore text at the bottom of the card, the creatures are trapped on a rock (possibly an asteroid.) Someone left behind an encrypted log recording the existence of slivers, either an unlucky explorer or, perhaps, a scientist involved in experimenting with the creatures, which would be a nice callback to the Riptide Project
So they would print separate rare sheets, uncommon sheets and common sheets, and they would print more of the common sheets, less of the uncommon sheets and even fewer of the rare sheets." As stated earlier, it's been estimated that just 1,100 of each "rare" card was produced
This deck can stay alive not just with counterspells and stall effects like Propaganda, but also lifegain from Venser's Journal while drawing cards as fast as possible