My first two is the name for a circle's fundamental ratio, my last two are the symbol for an element, used to make signs stand out at night. Together, I'm a synonym for yearn.

One part of my name is sour, the other has bite, I’m more social than ready to fight.

I come from an egg, yet the egg came before me.

gold, black, or green is my armor's sheen though i have no sword to fight. i bear great stag and rhino's horns, yet fly to reach your height.

A swashbuckling cat wore me during his quest, To prove that a feline can be dressed for the best. I am England’s name for the back storage car part, And what a computer does to warm up and start.