Mythic Oddysseys of Theors p. 208
Two Heads. The amphisbaena has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned and knocked unconscious.
Multiattack. The amphisbaena makes two bite attacks. Bite. Melee Weapons Attack: +6 to hit, reach 5ft., one target. Hit: 6 (1d4+4) 1d4+4 piercing damage and 4 (1d6+1) 1d6+1 poison damage.