"hare" is Russian slang for a stowaway or a passenger travelling without a ticket.
https://lenta.ru/news/2018/11/21/zapis
The rough transcript goes as follows
0:00 OK, so we done everything, lowered gear for verification, retracted gear, we're good, no failures, nothing is visible.
0:09 I think the "hare" [term for a stowaway] was not capable of inflicting... ehm... damage of any kind
0:17 We're carrying on with the flight