Asian fossorials that dig, web, and disappear. Give one eight inches of substrate and it will build a tunnel system with a webbed funnel at the mouth and spend most of its life inside it, coming out to grab prey and vanishing again.
The trade calls them pet holes and the trade is correct. What you get in exchange is speed, appetite, and on several species genuine iridescence: the blue forms out of Thailand and Vietnam are as blue as anything in the hobby. Growth is fast for a tarantula.
The taxonomy is chaos. The same animal circulates under a described name, a locality trade name, and a color-form nickname, sometimes from the same vendor. That fragmentation creates real arbitrage on the price side, and it is the single genus where checking the species page before paying a locality premium saves the most money.