The archetype that presents the self-defeating, childish or trickster part of the personality is called the Demon/Daemon
Explanation:
In Jung's psychoanalysis there are certain archetypes that are present in all humans regardless of their culture or affinity to each other.
These archetypes are common to all the humans on the planet and cannot be escaped from.
One of the archetypes is the one of the Demon who is always wrecking havoc in the unconscious of the person and is a trickster.
The demon plays tricks and makes the mind go childish and take up a self defeatist attitude towards the life they are leading.
