What am I riddles

I live in lakes and rivers. I eat fish and birds. I have four legs and a long tail. I have lots of pretty teeth. I am a...

Physicists have built devices to move me very fast. My last seven letters can be commonly found in newspapers, magazines and journals. What am I?

Wash it and it isn't clean. Don't wash it and then it's clean. What I Am?

I eat insects. I live in the pond. I hop. I am green. What am I?

I have four legs but no tail. Usually I am heard only at night. What am I?

I'm tall when I'm young, I'm short when I'm old, and every Halloween I stand up inside Jack O Lanterns. What am I?

I taste sweet and juicy. I smell fruity. I feel rough and wet. I look like a bumpy ball. What am I?

I go in hard. I come out soft. You blow me hard. What am I?

I can be as thin as a picture frame but my insides have many things you can see. What am I?

I am a five letter word and very strong. I become single when you remove two letters from me. What Am I?