Adventure Comics (vol 1) #339 VG

"Hunters of the Super-Beasts!" On the planet Vorn, Beast Boy from the Heroes of Lallor has taken residence and led the beasts and monsters there against humans. On his own planet of Lallor, Beast Boy was shunned by his fellow planet natives due to his terrible powers to transform into animals and monsters. He was tired of humans and decided to live his life as an animal, on Vorn. The Legion of Super-Heroes came to Vorn to help the humans out. Vorn somehow escapes to Earth and captures the Legion of Super-Heroes, putting them in his version of a zoo...where the heroes are in cages. The Legionnaires break free and Beast Boy escapes in the form of a dog. He befriends a girl who is about to be killed by an animal and Beast Boy sacrifices his life so the girl can live."The Night of March 31st" An April Fool's Day story with lots of errors. Reprinted from Superman #145.