Blanket sleepers sometimes depart from the standard design by incorporating unusual or uncommon features.
Drop seat One of the features most commonly associated with blanket sleepers in the public imagination, the drop seat (also known as a trap door or butt flap) is an opening in the buttocks area, traditionally closing with buttons, designed to allow the wearer to use the toilet without removing the sleeper. Drop seats were very common on sleepers made before the 1950s, but today they are rather rare. (Similar drop seats were also a common feature on the traditional union suit.)Modern versions of the drop seat often replace the buttons with snap fasteners.Snap front/legs Some sleepers, especially in infant sizes, replace the usual front zipper with a front opening closing with snap fasteners. In infant sizes, this opening usually forks at the crotch, and extends down the insides of both legs to the ankles, in order to give access for diaper changes.
This design tends to be less effective at eliminating drafts than the zipper closure, and is most often seen on lighter-weight sleepers designed for warmer weather.Some infant-size blanket sleepers made in the 1960s featured an ankle-to-ankle zipper through the crotch, serving a similar function.Snap waist/back Two-piece sleepers sometimes fasten around the waist with snap fasteners.
This is most often seen on so-called grow sleepers, made mainly in toddler sizes, with features designed to extend the useful life of the garment by compensating for growth in the wearer. These are usually made in lighter material than one-piece sleepers, with an especially high waist, two rows of snaps on the top piece, a back opening on the top piece also closing with snaps, and turn-back cuffs.Two-piece sleepers made before the 1950s often fastened similarly around the waist with buttons.
Blanket sleepers sometimes depart from the standard design by incorporating unusual or uncommon features.
gets a pink bunny costume sleeper, complete with bunny-ears on hood, attached mittens and bunny-slippers, from his crazy Aunt Clara "That worked under the delusion that I was perpetually four years old, but also a girl",on Christmas morning at the tail-end of movie.
Little brother, Randy, wears printed blanket sleeper also at tail-end of movie Growing Pains Maggie Seaver (Joanna Kerns) wears a pink blanket sleeper with striped sleeve cuffs in a few episodes The Wonder Years Kevin Arnold (Fred Savage), wears a red blanket sleeper with striped sleeve-cuffs in a dream sequence in one episode The Torkelsons Mary Sue (Rachel Duncan), wears a blue blanket sleeper in one episode Almost Home (Spin-off series of The Torkelsons)
Mary Sue (Rachel Duncan), wears a red blanket sleeper with striped sleeve cuffs in a couple early episodes The Shining (1980 movie version) Danny Torrence (Danny Lloyd) wears a bright red blanket sleeper in night-scenes and morning scene towards the end of the movie Family Guy Peter Griffin sees, buys, and wears red adult-sized blanket sleeper he found at a department store and in next scene shocks everyone after rubbing sleeper-soles against carpet, causing static-cling in one episode. Baby Stewie wears a blue blanket sleeper in many episodes.
Blanket sleepers sometimes depart from the standard design by incorporating unusual or uncommon features.
Drawstring cuffs A common feature on sleepers until about the 1930s was turn-back cuffs closing at the ends with drawstrings, designed to fully enclose the wearer's hands. 
According to advertisements, these were intended both to keep the wearer's hands warm, and to discourage thumb or finger sucking. (These were mostly found on smaller sizes, but have appeared on Dr. Denton brand sleepers in sizes for children as old as 10 years.)
Costume sleepers Occasionally garments are made that are designed to serve a dual function, as both blanket sleeper and fancy dress costume (similar to the ones worn by American children on Halloween).
Animal costume sleepers are the most common, often featuring hoods with costume ears, tails, and/or hand covers resembling paws.
Other motifs such as superheroes or clowns are also sometimes seen.The use of the terms bunny suit and bunny pajamas as synonyms for blanket sleeper references the persistent cultural meme of a blanket sleeper fashioned as a (usually pink) bunny costume, with a hood, long ears, and puffy tail.
A related phenomenon in Japan, of footless, lighter-weight, hooded, one-piece animal costume pajamas, is known there as disguise pajama or kigurumi (although the latter term can also refer to costumes that are not intended as sleepwear).
Blanket sleepers sometimes depart from the standard design by incorporating unusual or uncommon features.
Convertible feet Another variation replaces the permanently enclosed feet with "convertible" foot coverings resembling tube socks, that close at the ends with velcro, and can be rolled back to expose the feet when desired. Hood Attached hoods were occasionally seen on sleepers made before the 1920s, and as late as the 1940s the company that made Dr. Denton brand sleepers offered separate "sleeping hoods", designed to be used in conjunction with their sleepers, in sizes for both children and adults. On modern sleepers attached hoods are extremely rare, found only on a handful of sleepers for older girls and women, and costume sleepers.
Mittens Attached mittens were occasionally seen on sleepers made for infants, usually to prevent finger or thumb sucking, but also served the dual purpose of keeping the hands warm. Mittens can also be used on costume sleepers for both children and adults Quilted fabric Sleepers are occasionally made from a quilted fabric, incorporating a thin layer of polyester fiberfill batting for increased warmth.
Quilted sleepers using polyester foam as insulation were also made in the 1950s. Elastic back waist Sleepers in larger sizes sometimes feature an elastic band along the rear half of the waist, designed to provide a better fit by reducing bagginess around the torso.
Blanket sleepers in popular culture Poltergeist III Carol Anne (Heather O'Rourke), wears a red blanket sleeper with white buttons (instead of a zipper), from neck-to-crotch, as well as white vinyl soles and toecaps and white rib-knit sleeve-cuffs for the last two-thirds of the movie Ghostbusters II Baby Oscar wears a yellow blanket sleeper with a Winnie-the-Pooh applique in the night scenes towards the end of the movie Mystic Pizza Phoebe Travers (Porscha Radcliffe) wears a purple Carter's blanket sleeper with striped sleeve-cuffs about an hour into the movie A Christmas Story Ralphie (Peter Billingsley),
Blanket sleepers sometimes depart from the standard design by incorporating unusual or uncommon features.
Minor variations Side zipper A rare alternative to the center front zipper is the "side zipper", running from the neckline near one shoulder (usually the left) to the outside or front ankle. This is most commonly found on sleepers with an elaborate printed design on the front, in which case it serves to avoid disruption of the image. An even rarer variation is to have zippers on both sides. 
Back zipper Although back closings using buttons were common on sleepers made before the 1950s, zippers in the back are extremely rare in regular children's sleepers. A back zipper makes it difficult for the wearer to remove the sleeper for bathroom use. However, a number of examples in regular sleepers existed in the 1950s and 1960s.
Back zippers can however often be found on sleepers for some disabled wearers where it is an advantage to prevent the wearer removing their sleeper, especially those who wear diapers and have a tendency to remove them. Self-fabric feet Sleepers made in sizes for infants who are too young to walk often omit the slip-resistant soles on the feet, instead having soles made from the same fabric as the rest of the sleeper.
This is also occasionally seen on sleepers for older girls or women.Bound feet On sleepers made since the 1980s, the soles of the feet usually attach to the upper foot pieces with an inward-facing seam. In preceding years, it was more common for the seam to face outward, and to be covered with a narrow strip of material, forming a kind of ridge around the perimeter of the sole.
This design was referred to in advertisements as a bound edge or bound foot, and was intended both to improve durability, and to improve comfort by eliminating a potential source of irritation.Molded plastic feet Around 1970, some sleepers were made with foot bottoms made from three-dimensional molded plastic.
This feature proved unpopular, and was quickly abandoned. Detachable feet Occasionally, rather than having permanently attached feet, sleepers will come with separate feet, similar to slippers. This is more common on adult sizes.
