Yeah, egg isn’t uncommon.
From your normal ‘chain’ stores (Pizza Hut, Dominos, etc) in South Australia you’ll only get basics like: bacon, ham, ground beef, pepperoni, capsicum, onion, mushroom, jalapenos, egg, pineapple, anchovies and various seafood stuff - all on a tomato or barbeque type sauce base.
Outside the chains, it’d be unusual *not *to get the additional option of things such as chargrilled capsicum, sundried tomato, artichoke hearts, cream and/or pesto-based sauces, eggplant and/or zucchini, and various cheeses such as feta or bocconcini. Some places I’ve personally eaten at have also offered pumpkin, pasta carbonara (yes, as a pizza topping - don’t knock it!), yiros meat with garlic sauce, corn chips with guacamole, and …oh, any number of things.
We’re all about ‘fusion cuisine’, doncha know. 
A local place near my work does a delicious vindaloo pizza - beef vindaloo curry topping, with young spinach leaves and sour cream added after cooking. (The spinach wilts with the heat and the combination of it all is super-yum.) They also make what they call the ‘Smokey’ pizza - it’s divine: double-smoked bacon, smoked chicken, smoked feta, onion, and (if you like that kind of thing) kalamata olives. I think I’m forgetting an ingredient or two, but you get the drift.
Pretty much, we’ll try anything once. I’ve yet to order anything that absolutely didn’t work as a topping, regardless of how esoteric it might have sounded.