Marvin was eight years old when he arrived at Jungle Friends on November 21, 2007 along with four other marmosets named Arnold, Gizmo, Ernie and Tuque. These boys were originally purchased by a research laboratory for iron toxicity studies; however, the lab found that marmosets were not good models for this study. Another investigator then wanted to 'use' them in schizophrenia studies! These boys narrowly escaped that fate. Fortunately for them, they were allowed to leave the lab and begin a new life at Jungle Friends.

Marvin and Tuque live together. Although both boys are a bit on the cautious side, Marvin is the bolder of the two; he is interested in all that is going on around him and not nearly as shy as Tuque.