A guardian angel might look exactly like a human or he might appear as a ball or beam of light, according to Telling Ministries LLC. In contrast, About.com says that some guardian angels do their work without taking a visible earthly form.
Guardian angels that appear in heavenly form usually have a beam or ray of light that epitomizes their heavenly essence, states About.com. In addition, guardian angels often have wings that signify their other worldliness. White is the most common color of a guardian angel in heavenly form but observers report seeing guardian angels in many colors. Guardian angels occasionally take on animal characteristics.
Other guardian angels look so much like humans that the people they interact with do not even know that they are talking to angels, explains Telling Ministries LLC.
Other times, the angels do not take a visible form at all and rather complete their work completely invisible to the human eye, explains About.com. These angels interact with the world and with humans but they do so in a way that humans cannot perceive.