I think I'll also do Humans before this is over...when I type in the subject box, the list of what I've done pops up, and I don't see them. Anyway...
They're a species of really tiny creatures with really big egos. They don't seem dangerous, but surprise everyone when they employ their shrink ray. And they know how to use whatever the energy is generated by the morphing cube to power their ships. At first, it's the females who are entirely in charge, and the males are slaves. Then, Marco inspires the males to start a war of the sexes with the females, and it's still going on in book two. Probably the part that sticks out the most to me is the dead captain thing.
I found the two Helamcron books amusing, but they were kind of annoying after a while. And I definitely liked The Suspicion better than The Journey. That second one was just mindless filler material and had little plot relevance.
At least it seems they got off the planet that time, or at least, they never came around again. Twice was probably enough for some of us LOL.