Hare Krishna Santa Clauses, a prefabricated creche, plastic lights and boughs, and a lone Salvation Army horn player are ushering in the Christmas spirit and trying to throw Cambridge shoppers into a buying frenzy.

Though the gobbles of Thanksgiving turkeys still ring through the hills of Massachusetts, city hall, retailers, charity organizations and religious groups seem determined to ram the Christmas spirit down the throats of Cantabridgians.

"We can't feed children reindeer meat," one of a pair of Hare Krishna monks said yesterday as he walked through Harvard and Central Squares handing out pamphlets and candy and asking for money.

Both Santas said they were from the International Society for Krishna Consciousness, which is collecting money for hungry boys and girls.

But a spokesman for the Society said yesterday the five Santa-monks in the Boston area collect money for the publication of books which "will spread Krishna consciousness throughout the world."

"To retailers, Christmas is a time when people buy more of what they were going to buy anyway," James A. Argeros, general merchandise manager of the Coop, said yesterday.

Among the many useful household items the Coop is selling are Harvard insignia toilet seats at $16.50, "slightly pornographic" Massage Mobiles and imported Kitchen Witches that ward off evil spirits and bad coffee, the household furnishings buyer said yesterday.

Sales are up at the Woolworth's in Harvard Square this year, too, despite the fact that the store is going out of business January 17, Gordon R. Carr, store manager, said yesterday. He said the store's lease is expiring and the rent will go up at that time, becoming too high for the store to remain profitable.

Outside the Coop a college student in the uniform of the Salvation Army played Christmas carols with a money tin by his side. "My music and time are the only things I can give to poor people," he said.

"We should put Christ back in Christmas and take the U.S. out of South Africa," Donald Jensen, a government teaching fellow, said yesterday as he stood outside the Coop