Gullible
/ˈɡʌl.ə.bəl/ adjective easyEasily fooled or tricked because of being too trusting.
The gullible tourist paid triple the normal price after believing the vendor's obviously exaggerated claims.
Memory Trick
Gullible sounds like 'gull,' a seabird famous for swallowing almost anything tossed its way — a gullible person swallows any story without question.