Marvin is an ostrich that appeared in "iMeet Fred." Spencer bought him because his Magic Meatball told him to. Marvin has not made another appearance since. Marvin is shown to like root beer and biting Spencer's pants. He may be intelligent, because when Spencer was going to see Fred he said, "Marvin, I'm going to Idaho! Stay off the Internet!"
After everyone got back from Fred's treehouse, they made a video with him. In one part of the video, Spencer says he and the ostrich are getting married and were wearing matching ties, as shown in the picture above.
In iBloop, a blooper is shown where the ostrich ducks so you cannot see him. Spencer says "Woah!" after the ostrich comes back up.
In iReunite With Missy, Spencer asked Chuck Chambers if he wanted; "Money, power, an ostrich?!", so it is possible he still owns Marvin and keeps or brought him somewhere else.