How to create custom controls in visual studio 2015

I found saw some interesting control in someones code that is not in visual studio 2015 designer tool box and am wondering how someone was able to create it.

Here is how it looks

this.control1 = new Mycontrol();
this.control1.AutoSize = true;
this.control1.BackColor = Color.White;
this.control1.BackgroundImage = (Image) Resources.background1;
this.control1.BackgroundImageLayout = ImageLayout.Stretch;
this.control1.Location = new Point(-2, 100);
this.control1.MainMenu = 0;
this.control1.MainMenuName = (object[]) null;
this.control1.Margin = new Padding(0);
this.control1.Name = "control1";