Agni is one of the first gods who got a human shape.
Fire offering was already very important in the pre- Vedic period.
This fire offering was embodied by Agni. Agni is the brother of Indra.
He is depicted with 2 heads and 3 legs. He has two up to seven arms.
In each head, he has seven fiery tongues by which he licks the Ghee.

Attributes:

Battle axe (Parashu):
The axe symbolizes the victory on ignorance/ evil.

Flame (Agni) :
It is used as weapon of war and as an important component of offerings. It is one of the oldest weapons and often carried by Shiva. It may be held by the fire god Agni or may issue from his body. It symbolizes destruction and afterwards creation.

Rosary (Akshamala):
It is symbol of the never ending cycle. It is a string of beads.
In Hindu tradition, Brahma, Shiva, Ganesha and Saraswati also carry it.

Spear (Skula) :
This is an indestructible weapon.

Riding Animal :

Agni rides on a ram / goat.
The ram / goat symbolizes the earthly fire and energy.