Madagascar hissing cockroaches, and the hiss is real: forced air through modified spiracles, used in defense and in male competition.
Large, slow, climbing, long lived and genuinely docile, which is why they end up in classrooms and outreach programs more than any other invertebrate. They need a barrier at the top of the enclosure because they climb glass well.
Two things worth knowing. Much of the North American stock is hybridized across Gromphadorhina and related genera, so a specimen sold as G. portentosa frequently is not purely that, and lineage claims should be treated with skepticism. And several US states restrict or require permits for possession. Prices are near zero either way.