Ex-Reality Star Pleads Not Guilty by Reason of Insanity in Child, Dog Sex Case

Former A&E personality Tony McCollister -- who is charged with raping a child and having sex with two dogs -- says he's not guilty by reason of insanity ... and he wants to get his head checked.

McCollister is facing 26 felony charges related to sex with a minor under the age of 10, plus 4 misdemeanor counts of sexual conduct with an animal ... and on Thursday, he entered his plea and filed a motion asking the court to order an evaluation of his mental state at the time of the alleged crimes.

In Ohio -- where McCollister is charged -- a defendant must prove they did not know right from wrong at the time of the crime to be considered not guilty by reason of insanity.

As we told you ... a judge already ordered McCollister to stay the hell away from kids and dogs ... and, specifically, not to have sex with animals.

In 2015, McCollister appeared on the short-lived A&E show "Neighbors with Benefits" about a group of swingers. Public scrutiny led to the show being axed after only 2 episodes.