One of my favorite features of El Capitan is the Cursor locator. I use a large display and the display on my MacBook Air when I am working at my home office. A lot of times I will have a spreadsheet on the MacBook Air’s display and our database (appropriately named K9) on the other large display. From time to time, I might lose track of the cursor. Where I used to just start cussing out my Mac with Grace asking “what’s wrong, dear?”, now all I have to do is shake my mouse or wiggle my finger on the trackpad and I have mega-cursor and know just where it is.
Okay, so let us just imagine that you might need to wiggle your mouse or trackpad in doing illustrations or something. That jumbo cursor might get in the way. You can disable this curser action if you want. Go to System Preferences > Accessibility > Display and deselect Shake mouse pointer to locate.