This is an animated gif of American professional strongman competitor Brian Shaw lifting 1073 pounds / lbs. That's the same as 486kg.
OK. I don't know WTF is going on here. All I know that this is from some sort of modern theater play. The guy is basically hitting some sort of meta pole off a metal post. Somebody has added the text "Oh Children, It's Dinner Time" to the gif. This is often used as a reaction gif whenever somebody wants to let everyone know that they're about to lay the smackdown.
This is an animated gif of a crying Indian / Native American. The way he turns his head as a single tear rolls down his face makes this a great reaction gif for whenever somebody says or does something that upsets you. Not sure where this is from. If you know, please post the source in the comments below.
This is an animated gif of actor Eddie Murphy nodding. It's obvious that he doesn't actually agree with the person and that he's kind of taken aback by what has just been said. This reaction gif sums up how I feel when a friend of mine starts talking about conspiracy theories.
Edit: Info was wrong. This is actually John Simm...
This is an animated gif of actor Simon Pegg crying at what looks to be a computer. This reaction can be used whenever you see something online that upsets you. Or... you could use it sarcastically. Whatever floats your boat. Simon Pegg is well known for his roles in Shaun of the Dead and Hot Fuzz.