feed me and it will give me life. but give me a drink and i will die. what am i?

I can serve others, but I cannot talk. You might see me in a cooking pot.

I’m slippery, I’m slimy, I can make things less difficult, after all it’s in my name. Oh yeah, I’m also a musical.

I used to be part of a powerful symbol. I am also the name of fictional ninja. I can be made into jewelery and figurines.

My colleagues are by no means thick, but without me they just can’t click. Combined they might just pull more weight, but I’m what lets us innovate. Some call us equals but don’t you see? There’s four of them and one of me!