Apex domains cannot have CNAME records.
Question and response
Question
dig ninja. NS
Answer
ninja. 5 NS v0n2.nic.ninja.
ninja. 5 NS v0n0.nic.ninja.
ninja. 5 NS v0n1.nic.ninja.
ninja. 5 NS v2n1.nic.ninja.
ninja. 5 NS v2n0.nic.ninja.
ninja. 5 NS v0n3.nic.ninja.
Authority
The response has no authority records.
Additional
v0n0.nic.ninja. 165455 A 65.22.20.4
v0n1.nic.ninja. 165455 A 65.22.21.4
v0n2.nic.ninja. 165455 A 65.22.22.4
v0n3.nic.ninja. 165455 A 161.232.10.4
v2n0.nic.ninja. 165455 A 65.22.23.4
v2n1.nic.ninja. 165455 A 161.232.11.4
v0n0.nic.ninja. 165455 AAAA 2a01:8840:16:0:0:0:0:4
v0n1.nic.ninja. 165455 AAAA 2a01:8840:17:0:0:0:0:4
v0n2.nic.ninja. 165455 AAAA 2a01:8840:18:0:0:0:0:4
v0n3.nic.ninja. 165455 AAAA 2a01:8840:f4:0:0:0:0:4
v2n0.nic.ninja. 165455 AAAA 2a01:8840:19:0:0:0:0:4
v2n1.nic.ninja. 165455 AAAA 2a01:8840:f5:0:0:0:0:4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0