For Christmas 1984, the pitty-pat of little feet won't be reindeer but robots.

All over America, rich but innocent children asleep in their trundle beds will be awakened by the $300 Omnibot. Its maker describes it as a programmable electronic robot with onboard microcomputer and tape deck.

Translated into Earth talk, that means you can teach it to walk down the hall and play back a recorded message, a song, or even loud threats -- whatever you think necessary to wake your child (or spouse, or other resident sleeper). You can also, the maker claims, program Omnibot to serve tea and cookies -- or something stronger, which your guests will no doubt need after they see Omnibot. (Even in that mode, it is not called Butlerbot, no matter what the provocation.)

When movies are full of giant, mechanized worms, when presidential candidates start talk of "star wars" defense, when real spaceships lasso wayward satellites and when television is full of Nazi reptiles, it should not be surprising that children are seeking allies among robots.

The robots now occupying the United States are more or less friendly invaders from Japan, where the children have been playing with robot toys for two or three years. A small expeditionary force made a feint in the United States last year, but was vanquished then by the Cabbage Patch Kids related story, C4 . Like presidential candidates, the popularity of the toys seems to depend a great deal on their abilities as television stars.

The term robot comes from the Czech word robota, meaning, according to various accounts, either worker or slave labor. Actually, all but a few of the so-called robots in the stores are to real robots what dolls are to people -- they don't really work, they're only for play.

Robert Bernhard of Tomy, which makes Omnibot, Verbot and Dingbot, says, "We'll be able to sell all we make. We've already sold more robots than have been sold in the entire history of robotics. Though they came from our Japanese division, we had to modify them, for instance, to make them roll over shag carpeting."

Omnibot, at $300, is one of the most elaborate and expensive toys in the invasion. It isn't, however, the most elaborate one of its kind. At least six companies are making other, more expensive, models, up to $7,500, but their production is small and delivery not nationwide.

Tomy's Verbot ($65) responds to commands given through a wireless microphone remote control. It can make the same moves as Omnibot, picking up, carrying and putting down objects. Verbot smiles by lighting up its eyes and mouth. Dingbot ($10) isn't a worker, but it moves forward, stops and shakes its head when it encounters an obstacle, fusses about it, turns right and moves away. March of the Man-Made Men

The less expensive, small manipulable "action figures" -- Transformers, Gobots and others (many under $5) -- change before your very eyes from automobiles and trucks into robot figures.

The robot action figures, defined by some as dolls for boys, serve the same function that trucks and cars and toy soldiers did for earlier generations -- they give fantasies some reality. And, in this day of women astronauts, girls may like these toys just as much as their brothers do. Some of the figures even come with histories and plot lines already furnished to whet children's imaginations.

Tonka Toys got the jump by introducing Gobots last January, generating $100 million in orders. Gobots are three inches high; Super Gobots are five inches tall. They cost from $4 to $10. Both can be folded into sports cars, airplanes, motorcycles or dump trucks to escape the enemy.

Bandai, the largest toy company in Japan, developed and sold them in Japan and tried to introduce them here earlier, but, according to Barbara Gardiner at Tonka, the toys needed a story line. So Tonka made a play set that told children about the good Gobots and the bad Gobots from the planet Gobotron. A television cartoon, "The Challenge of the Gobots," is already spreading the myth that the Cy-kills are trying to capture the planet Earth.

In May, Hasbro Bradley Inc. introduced Transformers, made by Takara of Japan (at a suggested retail price of $2 to $26). Transformers, as do Gobots, change in your hand from airplanes or other vehicles to robots. The company plans to ship $80 million worth of toys, and it still has a large number of unfilled orders.

Japanese manufacturers are shipping Diakrons, sets of 14 different robots. Another brand, Godakins, are robots that can be made into three different kinds of toy vehicles.

Masters of the Universe, another group of action figures, have a suggested Dungeons and Dragons type of play. To Move Moon Mountains

Among the toys in the middle price range are motorized modular construction toys that are put together to make moon vehicles. Robotix, a modular building system of 59 to 87 pieces, comes with two to four motors and several switches. Made by Hasbro Bradley Inc., it costs $40 to $60. With these parts, the child can make everything from a moon vehicle to crater creatures. LEGO, the building system, this year comes in sets for space machines as well as Legoland castles. They Walk, They Talk

In California, John Peers at Androbots is making highly sophisticated robots, in small, medium and large functions. He's shipped a thousand this year and is now producing 300 a month. He describes them:

FRED, (Friendly Robotic Educational Device), for $499, understands 57 words, moves, draws squares and circles, writes numbers and letters. FRED is controlled by a hand-held infrared remote unit or can be plugged into a personal computer;

TOPO (Topographical) can say or sing anything you type into its master computer, which controls it by an infrared unit. TOPO toddles around with two trays that will hold four cans of beer or chips and dips. TOPO can count, perhaps even up to its $1,595 price;

BOB (Brains On Board) is a full computer, ultrasonic. "BOB understands what's going on. He could collect dishes and take them to the kitchen or patrol warehouses at night," Peers says. BOB costs $7,500. Nonmechanical Marvels

For those who would rather play in the 13th century, one company sells the Ideator, a kit to make wooden Leonardo da Vinci models.