Garudapurana 3.22.40

3.22.40

lalāṭe trīṇi dīrghe tu same dvau saṃprakīrtitau /
sarpākārastu yo matsyastasya śiśre prakīrtitaḥ //

on the forehead three [lines] are declared to be long, and two equal. / A fish that is serpent-shaped is proclaimed to be on his penis;