This paper presents the development and analysis of a quadruped robot prototype designed to achieve statically stable rear leg standing. Existing quadruped robots such as Mini Cheetah and Go2 are versatile, but rely on dynamic movement to remain stable. We present a robot prototype that can transition from quadrupedal to an upright stance while remaining statically stable throughout using a tail. This Tail-assisted Transition Robot (further: TT-Bot) utilizes electric actuators and combines aluminum and 3D printed nylon components to form a lightweight yet robust structure. It aims for a functional approach through strategic motor placement and a belt-pulley system for knee joint actuation. Kinematic analyses guide the control strategies implemented to manage the transition. Initial results from simulations and physical tests indicate that TT-bot can effectively maintain an upright stance under controlled conditions. Stability tests indicate successful static stability across slopes from −10◦ to 5 ◦ . A payload test showed that it was able to transition with a payload of 3 kg. Challenges during transition remain with steeper inclines and higher payloads.