The Mark of the Guard is a special mark given to members of the Lion Guard. It is in the shape of a roaring lion's head. Each member's mark changes color to match their own pelt. It is given to them by the leader placing their paw over their left shoulder.
It seems to be well-known as a representation that the animal that it is bestowed upon is a member of the Guard.
In trying to figure out how to defeat Scar, Kion and his guard travel deep into the lair to discover the secret to defeating great evil is them. From which a painting shows Askari and his guard coming together to form the Mark of the Guard.
An early version of the mark was a lion paw print.
There are many mistakes regarding the Mark of the Guard in both The Lion Guard: Return of the Roar and the TV series. The Mark may be on the wrong shoulder, facing the wrong direction, missing entirely, be present in multiple places on one character, or, in the case of Fuli, be replaced with or overlapping with another marking.