In the series is Carl Reel an Inhuman? Is his origin explained? In the comics the powers comes from Loki, but there is no mention of that in the TV series.
In Agents of SHIELD, Carl Creel is not an inhuman. In fact, he gained his powers via Wolfgang von Strucker's experimentation. According to the season five episode "Rise and Shine," it was part of Project Destroyer of Worlds, a project whose goal was to recreate the super soldier serum with the added effect of giving its user the ability to take on the properties of any material they touch. Creel was one of the test subjects and was successfully given those absorbing powers. However, he was not ultimately selected to be the Destroyer of Worlds, a title bestowed upon the HYDRA-born teen Ruby Hale.