A small toy developer in Manhattan Beach is appealing a judge’s ruling that Nintendo of America Inc.’s Pokemon characters do not infringe on its trademark.

Morrison Entertainment Group Inc., founded 12 years ago by two senior executives of Mattel Inc., sued Nintendo and its licensees in March 2000, claiming the Pokemon characters are confusingly similar to the “Monster In My Pocket” characters that Morrison developed more than a decade ago.

An L.A. Superior Court judge ruled in Nintendo’s favor in August, and now the two sides are preparing for Morrison’s appeal in December.

Pokemon, originally called “Pocket Monsters” before coming to the United States in 1998, is similar to Morrison Entertainment’s miniature monster toys as well as its characters in video games, on clothes and in other applications because it uses a similar name and concept.

“Lo and behold, (Nintendo) came up with small, pocket-sized monsters, referred to them as ‘Pocket Monsters’ in every place but the U.S., and changed it here to Pokemon,” said Joe Morrison, co-founder of Morrison Entertainment.

The initial ruling was made in favor of Nintendo largely because the judge concluded that “Monster in my Pocket” characters are not familiar enough to cause confusion.

“The judge was saying that their name was not a famous name, so that might have some effect on the standard of proof as to whether a likelihood of confusion exists,” said Alan Clark, Nintendo’s lawyer. ”

The “Monster In My Pocket” toy line was sold worldwide and licensed to Matchbox Toys USA Ltd., now part of Tyco Toys Inc., and later branched into trading cards, comic books, clothing, lunch kits and an ABC show. It generated annual sales of $100 million. The “Monster In My Pocket” characters were later licensed to a Japanese video game maker for Nintendo, but not to Nintendo.

Pokemon reportedly grossed more than $1 billion in 1999 in the United States alone.

“The law is not, nor could it be, that only the big guy can sue,” said Brian Lysaght, Morrison’s attorney. “It’s whoever had the senior mark can sue. They’ve effectively put us out of business because everybody thinks we’re a rip-off of Pokemon.”