Dr. Vent

"I'M NOT GOING TO EAT YOU, I SWEAR! Liar! BE QUIET! He's been been isolated for too long! SHHH!"

- Dr. Vent

Dr. Vent is a minor NPC character who appears in Mario + Rabbids Sparks of Hope, located at Pristine Peaks. He is a male Rabbid who is a scientist. Dr. Vent wears a blue coat, black gloves, and orange hat with black googles. He has been alone at Pristine Peaks for three days, causing him to go insane. He loses his mind multiple times, and even calls the heroes spies. Dr. Vent also has a lab.

Mario + Rabbids Sparks of Hope
After the heroes clear the blizzard in Pristine Peaks, they can find Dr. Vent, who has a side quest named Dr. Vent's Frozen Oddity. Dr. Vent tasks the heroes to remove a saboteur in his lab, with the Spark Zephystar guiding them. Inside the lab, the saboteur is actually a Darkmess Puddle, and the heroes must clear it out in a battle.

After the battle, Dr. Vent thanks the heroes and apologizes for his behavior earlier, but loses his mind again and accuses the heroes as being spies. Zephystar then tells the heroes that Dr. Vent has been alone for three days, with Beep-0 being confused. Zephystar then joins the heroes on their adventure.

Memory bio
I am unable to avoid thinking about Dr. Vent, a "scientist" we met who was ill-advisedly using the hot air flowing from a mask-like aperture to unthaw a monstrous-looking Rabbid encased in ice that he discovered in a cave!
 * DR. VENT

''To call this ill-advised is an understatement. His assistant convinced us that his erratic behavior was caused by extreme isolation - all seventy-two hours of it.''