The monster who went on a shooting spree at two New Zealand mosques only had one concern after his arrest: how many people he killed in the bloodbath, according to a new report.

Brenton Tarrant, 28 — who gunned down 51 people and wounded 49 at the Al Noor Mosque and Linwood Islamic Centre in Christchurch on March 15 — was unconscious when authorities first rammed his vehicle off the road and took him into custody.

But once he came to his senses at the police station, he started asking officers about the death toll in the attack that officials have declared an act of terrorism, The Australian reported.

“How many did I kill?’’ he asked repeatedly, according to the report. “How many did I get?’”

Authorities were still trying to come to grips with the full scale of the carnage — and did not answer Tarrant, according to the report. At that stage, it was unclear whether they knew the count themselves.

Tarrant pleaded not guilty in June to 51 charges of murder, 40 charges of attempted murder and one terrorism charge.

Prior to the killings, which were livestreamed on Facebook, Tarrant posted a far-right screed online that laid out his desire to “incite violence” against Muslim people.

Michelle Grossman, an expert on violent extremism at Deakin University in Victoria, Australia, told the outlet that comparing the kill count is “an established phenomenon.”

“This is a very well established and almost old-fashioned way of dehumanizing the victims, turning them into numbers rather than people,” she said. “It’s also fairly common to see discussion around victims of such events and massacre in terms that are redolent of predator and hunting culture, such as ‘kill-count.’”