Aliens that do not understand how well humans can mimic some noises. -- Gallifreya
When headed into uncharted, or barely charted territory, when facing danger, it is best to have at least one human aboard your ship. Yes, they are frightening deathworlders, but they also understand this and endeavour to be less frightening so they can pack-bond with you. They are also, and the K'veth are discovering, prone to annoying pranks.
Bob could impersonate any noise on the ship, and used that frequently for 'laughs'. He was the most skilled at it, and could even do other crewpersons' voices. Thankfully, he was not good enough to fool the shipboard computer. He would carry on conversations with the Skitties at random moments and, overall, was a pain in the K'veth's anatomy.
He even picked up more than a few choice phrases in K'vethi, despite allegedly having the wrong mouth shape to pronounce it. One of his most-used ones was, "I can understand more than you think, you know." Especially when other K'vethi were talking about him in an unflattering way.