Another one of these God-like aliens that are supposed to be massively powerful and the Enterprise has no chance at resisting and completely daft in appearance. Just like with Armus, if you want to sell the concept of omnipotence, then you have to package it correctly. Nagilum was an other-dimensional creature that, for all his power and ability, could not understand human creatures, especially the concept death. So, this dimensional explorer/scientist that has the ability to manifest itself in the middle of space, create a composite image of itself that somewhat resembled a human face (ostensibly to put the crew of the Enterprise at ease as it announced it was going to kill a third of them) and can't understand the basic concept of the end of a life-cycle? The universe is a big place, but there are basic rules to pretty much everything, and asking us to accept that this thing is conceptually completely unaware of the finite capacity of life-forms? This is the problem with trying to push the envelope in creating strange new life for the Enterprise to encounter. Give credit for imagination and the willing suspension of disbelief and all that, but this thing undercuts its own threat level in that it can't understand basic notions life and death. Everything in life ends at some point and that is a universal constant. In the Original Series, the failure to properly represent the danger level of the species rested with the inability of the make-up guys to create something with as few fake-looking bits as possible -that the audience could accept. In the Next Generation, it was the writers who failed the audience. They created creatures like Armus and Nagilum that were flawed in what they were capable of and what they wanted to achieve. Their goals were way beneath their scope for us to actually take them as credible and serious threats. So how does Captain Picard defeat this thing? He threatens to destroy the Enterprise via the auto-destruct sequence to deny Nagilum his experiment. If Nagilum has that much power to destroy a third of the crew with apparently very little effort, then isn't it logical to assume that he'd be able to halt the destruct sequence? Why waste time bantering with Picard at all? This thing is either incredibly lazy or not that much of a scientist. Either way, it's hardly a witty or dynamic resolution to a supposedly overpowering threat. You can't take Nagilum seriously, particularly when he looks like a reptilian version of those poor hairy-faced wolf people in Mexico.