CustomBlockBounce

public class CustomBlockBounce extends Block {

  //Constructor stuff
  public CustomBlockBounce (Material materialIn, String name //You can delete this and replace it with your block name) {
    super(materialIn);
    setUnlocalizedName(name);
    setRegistryName(name);
    MinecraftForge.EventBus.register(this);
  }

  @SubscribeEvent
  public void onPlayerStepOn(LivingEvent.LivingJumpEvent event) {
    if(event.getEntity() == null) {
      return;
    }

    // check if we jumped from a block that bounce
    BlockPos pos = new BlockPos(event.getEntity().posX, event.getEntity().posY, event.getEntity().posZ);
    if(event.getEntity().getEntityWorld().isAirBlock(pos)) {
      pos = pos.down();
    }

    IBlockState state = event.getEntity().getEntityWorld().getBlockState(pos);
    Block block = state.getBlock();

    if(block == ModBlocks.customBlockBounce) {
      bounce(event.getEntity(), 1.0f);
    }
  }

  private void bounce(Entity entity, float amount) {
    entity.motionY += amount;
  }

}