A grapefruit
what is a large yellow sour fruit
It is A...
It sounds like you are describing a Woodlouse Spider (Dysdera crocata). These spiders are brown with a distinctive large yellow or orange abdomen, and they are known for their behavior of rolling into a ball when threatened for protection.
A shaddock, alternatively known as a pomelo, is a large yellow citrus fruit native to southeastern Asia, or the tree which produces said fruit.
It sounds like you are describing a honey locust tree (Gleditsia triacanthos). It is known for its large thorns and produces clusters of yellow, fuzzy fruit pods that contain sweet, edible pulp. Be cautious around the thorns, as they can be sharp and cause injury.
A large brown bird of prey, with white head and tail, large yellow bill.
Ultimately the color will still be a shade of brown, because brown is any color with all 3 primary colors in it. Depending on the brown you start with, the resulting color could be very green or very orange. If you add a large amount of yellow, the result may be a very mucky yellow.
A wasp or hornet that is very large with a black bottom with 4 yellow stripes and a possible brown top could describe more than one type of wasp. It could be Digger wasps, or yellow jacket wasps.
Santol is a tropical fruit with a thick, tough skin that ranges in color from yellow to orange. The flesh is white or yellow, sweet, and tangy, with a texture similar to an apple. The fruit contains large seeds that are typically removed before eating.
An example of a multiple fruit would be the pineapple. The pineapple grows in tropical regions where it is warm most or all of the year. The pineapple is a single fruit that comes from more than one flower(and therefor more than one pistil) and the ovaries of each flower fuses so produce the large fruit.
Trees that drop large green fruit in the fall could be pawpaw trees (Asimina triloba) or Osage orange trees (Maclura pomifera). Pawpaw trees produce large, greenish-yellow fruit that is custard-like in texture and sweet in taste. Osage orange trees produce large, green fruit that is inedible for humans but is commonly eaten by wildlife like squirrels and birds.
Zoolanthellae is a substance that is present in large numbers in the cytoplasm of most marine invertebrates. It typically ranges in color from yellow to brown.