What things make a 2 year old boy toddler laugh?

He's almost two years old in less than a month. He for some reason doesnt like me anymore. When i come near him, he makes a terrified face, puts his hands out, looks away then screams! He even hits and tries to kick me! I used to make him laugh but i would have to do crazy stuff which would tire me out but it doesnt work anymore but he loves my little 9 year old brother n he makes him laugh alot. Help?? Btw he's a sporty and active little but he cant talk yet but babbles alot