It’s Halloween, fight fans! So, trick or treat?

Well, today hasn’t been a treat of a day for North American MMA.

As reported by Jim Genia, Bellator MMA suffered a rash of failed drug tests following Bellator 127. A total of four fighters tested positive per California Athletic Commission, for everything from modafinil to elevated testosterone-to-epitestosterone levels — or, about one out of five fighters on the card. Ouch.

Now, Titan FC has been dealt a blow, with tonight’s Titan FC 31 main event cancelled after Mike Ricci failed to weigh in at the contracted lightweight limit for his bout with Yoshiyuki Yoshida.

Originally, the bout was to decide the promotion’s first lightweight champion. But Ricci missed weight yesterday, coming in at 157 lbs. to Yoshida’s 154. The bout was thought to go on with Ricci and Yoshida fighting in a non-title affair at a catch-weight of 157 lbs, and Ricci penalized 20% of his purse. However, as reported earlier today, Yoshida has declined to fight. A source describes Yoshida as having “pulled out of the fight because he felt that it was unprofessional for Ricci to miss weight.”

The turn of events forces the Miguel Angel Torres vs. Desmond Green feature bout to the main event. We had a quick profile of the bout earlier at Caged Insider.

Titan FC 31 airs tonight on CBS Sports Network beginning at 10 pm ET or 7 pm PT.