Spelled this way, 까 is a relaxed rendering of -ㄹ까, the ending that floats a suggestion or wonders aloud: 한번 가 보까? 'shall we check it out?', 나도 챌린지 해보까? 'should I try the challenge too?' It expects the listener to weigh in rather than simply answer yes or no. Several lines here are other things wearing the same syllable — Japanese desu ka, the North Korean 오셨습네까, and the verb 까다 'to peel' in 이걸 다 언제 까.