Systems and methods for detecting a gas kick within a wellbore are provided. The system includes a rotatable tool including one or more acceleration sensors and/or oscillators. The method includes rotating the rotatable tool in contact with fluid inside the wellbore and detecting changes in rotational velocity of the rotatable tool to detect the gas kick. In other aspects, the method includes detecting a change in density of the fluid within the wellbore by at least one or more pressure waves to determine the gas kick within the wellbore.