Fun Riddles

Question: What word doesn't belong in this group? That, hat, what, mat, cat, sat, pat, or chat?

Question: What has four legs and can't walk?

Question: I am a big threat to humanity,
but you wouldn't get rid of me even if you could.

What am I?

Question: At the end of a long dark cave there is a monster made of lead. Be careful. One twitch of the finger and you will release it.

What is it?

Question: How high would you have to count before you use the letter 'A' in the spelling of a number?