Peter Martin is the son Dr. Lawrence Lloyd, aka Thorn. Born a normal boy, Peter left Millennium City with his mother after her divorce from Dr. Lloyd. When Lloyd became Thorn, the idea of a plant based super villain team appealed to him. He also thought that he would "reclaim" his son and turn him into an heir of sorts for when he conquered the world. He used a more refined version of his plant antitoxin and Peter was indeed transformed. He lacks his father's power level and variety but his body has seemingly permenantly changed. Also, he seems to have mantained his sanity. When the Champions rescued Peter from Thorn and returned him to his mother, Professor Prescott came calling almost immediately. Peter was admitted into the school so that he could be monitored for mental illness like his father's, learn to use his powers, and be kept safe from Thorn's attempts at reclamation. Peter gladly joined the other members of the Class '09 and while he holds no love in his heart for his estranged (and deranged) father, he does appreciate the power he has been given. Sentinal is a little forelorn. He knows that his presence might actually be a danger to the other students and faculty if his father comes calling. He also knows that he lacks the power to deal with him one on one. He appreciates the abilities of his "team" but also knows that they have yet to face anything stronger than an overconfident Bulldozer and a few ninja. Peter worries about his mother and calls her often. "Hey Aria, your flowers want you to put them closer to the window." Sentinal has plant based powers. His powers are mostly physical at this point. He can communicate and control plants but these abilities aren't very effective unless the plants are capable of movement. He can cause a large thorn-like spike to protrude from his wrist that inflicts a degenerative, but not fatal poison if he can pierce the skin. He can also cause a cloud of choking spores to eminate from his body. Finally, he has superhuman strength at a high level, however it is very tiring for him to use. IF he's too tough lower is "strength of trees" to +30. If he's not tough enough, raise h is dex to 18 or 20. An unusual looking boy about 12, with brown tough skin (barklike even!) and green hair and eyes. His hair is indeed hair and not leaves, his skin while unusual looking still feels like skin, if a little rough. As Sentinal, he wears jeans and a t-shirt. He doesn't really disguise himself when he leaves campus.

His mother knows of his powers, yes, but she is unaware that he is active in the superhero community, something she would not be pleased with. As such, Peter avoids media attention whenever possible.