Sea monkeys. 3-D specs. Hypno-coins. Ant farms. Kryptonite rocks. Miniature submarines made from cardboard. All available for a buck or less from the back page of comic books. And we blew our weekly allowance on these rip-offs, only to be disappointed when they turned out to be total crap.   But what if these bogus products had side effects not advertised? In horror master Hunter Shea's MAIL ORDER MASSACRE, sometimes you do get more than you paid for . . . JUST ADD WATER It's been years since David and Patrick flushed away the dead Sea Serpents they got in the mail. After thriving in the toxic stew of pollution, strange, slimy creatures now rise from the sewers. Once the screaming starts, David and Patrick realize that their childhood pets really did come to life. With a vengeance. They're massive monsters. . . and ravenous for human flesh!   OPTICAL DELUSION Martin punishes his son for wasting his allowance on a pair of cardboard X-ray specs. But when Martin tries them on, he's stunned to see through walls and clothes. But the novelty becomes a waking nightmare when the glasses burn into his face and he starts seeing horrifying apocalyptic visions no mortal man was ever meant to see. Images that turn him from a husband and father to a bloodthirsty homicidal maniac . . .    MONEY BACK GUARANTEE With her son's heart set on piloting his own nuclear submarine, Rosemary orders the craft advertised on the back of a comic book. But when her son nearly drowns in the swimming pool, an enraged Rosemary complains to the Better Business Bureau. The company's customer service center retaliates with threatening phone calls. Then her son and husband disappear. Now it's all-out war and Rosemary wants her $1.99 back!   Praise for Hunter Shea   "A lot of splattery fun."--Publishers Weekly