Humans are nowhere near being the most common creature on the earth. Depending on what you consider a "creature", you could think of microbes or bacteria... otherwise, you might consider the fact that insect life takes up a massive portion of the total number of living things. There are many, many more ants than there are humans on this planet.
The most common creature in minecraft are cows, pig, chickens and shepp. But it also depends on the seed
The atmosphere. a jelly fish and humans
Most animals are coelomates, including humans.
The animal that is the most emotionally complex besides the human is the monkey. Monkeys are very closely related to humans.
humans
human beings. besides that, hippopotomuses.
The most common ailment among any humans is the common cold.
The most common ear problem is an ear infection.
The most intelligent creature after humans is often considered to be dolphins. They have complex social structures, advanced communication systems, and exhibit problem-solving abilities.
Mars
I guess you mean by the most common form of sugar, and that is it, then it will be Lactose
Gorillas are generally agreed to be the most intelligent living primate besides humans.