Insane Lincoln is an alter-ego of Lincoln.
He looks like Lincoln, but with an orange eye color. His clothing and hair are completely orange, too.
Unlike his original counterpart, Insane Lincoln is aggresive and he hates everyone. He tries to kill them, which in case made The Loud House be a show only for adults.
Jack-O-Lincoln is Insane Lincoln's Halloween alter-ego. Jack-O-Lincoln haves orange skin and eyes along with brown clothing, unlike Insane Lincoln.