Yeah it's a bug - you'll know it when you see it, and it starts spitting at you. It's got a huge gland thing for its ass, and drops the energy glands. Have a powered fridge handy as they'll expire on you fast.

Do you know where to find them? I feel like I have been all over this planet and can't. I need them to make a shield and a warp drive it seems.

You need to find the Big Butt Bugs that spit green goo at you, I have found them mainly in forested areas at night Cruise around after dark and you can see the glow from their backsides. The gland is a drop when you kill it but it also expires really really fast so have a fridge available close by. And by expires fast I mean it becomes unusable in one minute or less, maybe a minute and a half, something like that.