Of all the inventions that have been made over the years, I am generally considered to be the most remarkable. What am I?

I can sometimes be cracked, and you can usually find me in a trail. If I describe your mind, your thoughts are probably off the rail.

I’m an onomatopoeia, a sound effect, like brrr. I’m almost the name of a hoppity guy, a friend to a famous deer. I sound like bump, and slump, and a seven hump wump of Mr. Gump. If you’re missing your front teeth, I might be what comes out when you try to say sump. What word am I, the sound when a heavy object meets the ground?

I’m your favorite pastime of x and o. But then I went and lost my favorite toe. Good breath guises an innocent treat. Baby’s rattle, I can’t be beat.

Family with the thingamas, both jig and Bob, a name for a thing when it's name you forgot. Aquatic aristocracy has it with gadgets aplenty, It is grim, I'll let you in, Don't feed him four hours after twenty.