What does this Rebus Picture mean?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

You need to move three matchsticks to form three squares. Can you do it?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

Can you find the six hidden animals in the picture below?

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

What is red and smells like blue paint?

Solve the following series:
AZ, GT, MN, __, YB