Mary Test
Mary Test
Vital statistics
Age 21
Species Human
Series Johnny Test
Location Providence
Voiced by Ashleigh Ball

Mary Test is a major character on Johnny Test. She is the elder of Johnny's two twin sisters.


Mary is the elder twin of the two. She appears to be somewhere around twenty-one years in age. Though Mary wears pants, she seems to be more "girly" than her twin Susan (as was revealed when she decides to make a normal dress in the episode "Princess Johnny"). Mary has a light yellow T-shirt with a blue moon on it, long curly red hair, and a moon-shaped barrette. When she is seen without her glasses, her eyes appear to be green. Her eyes' color is the same as that of her mother Lila's. She often wears baggy blue jeans and light olive-green sneakers with the shape of an ivory-colored crescent moon and a white lab coat. Her bathing suit is a pink bikini, and her disco outfit is a pink tank top with purple shorts and silver boots. She also has outfits suited for certain controlled experiments, such as a high-tech diving suit, and a skin-tight yellow Hazmat suit. Both suits have her trademark moon on the side. When handling bio-hazardous materials (usually while performing surgery), she dons a surgical mask and a pair of blue latex gloves.


Mary is a super genius and the older twin sister of Susan and also the older sister of Johnny. The twins are smarter than Johnny's enemies, such as Bling Bling Boy, Mr. Black, and Mr. White, and Johnny often uses his sisters' brilliance to defeat them. Mary has been shown to be more sympathetic than her sister. Like her sister, Mary harbored a deep love bordering on obsession for the Tests' next-door neighbor, Gil Nexdor, and would have both liked to have been Gil's girlfriend, which often got them into fights and allowed Johnny to manipulate them, but the twins have since moved on; Susan started to date Bling Bling Boy and Mary started dating Juniper Lee's brother Dennis Lee. Like her sister, she attended school at the Porkbelly Institute of Technology (a.k.a "Porkbelly Tech" for short). Mary is more likely to credit less scientific and more science-fictional phenomena, which, although they evoke scorn and disbelief from her twin, often prove to be genuine in the end. Mary seems to be more level-headed than her twin Susan, and tends to be more conservative, speaking her mind much less than Susan.

Powers and Abilities


Mary Test is an expert on In all things scientific from Biology to Superlogy. She has performed many complex tasks and tests involving Super Powers, such as giving Johnny powers. Her intelligence allows her to quickly piece together facts and figure out solutions to problems with ease. With Mary's logic and guidance, Area 50-2 has completed various missions and survived life-threatening events, such as an alien invasion.


Despite being a researcher, Mary has been trained by Providence to defend herself. Mary possesses quick reflexes, as seen when she effortlessly dodged three Cyberdogs that Fusion Breach teleported into a containment room. Additionally, Mary is proficient with the use of firearms. In particular, she has used Freeze blasters and missile launchers to defend her allies from Fusion piranhas that attacked her and her allies on missions. When Dexter and Johnny were about to be attacked by a massive Cyber-hound in Abysus, she quickly jumped in front and fired her blaster at it until it slowly froze. Although Mary is generally able to take care of herself, there have been multiple times where her low accuracy with firearms and her low strength level have almost gotten her injured. Many times Mary has demonstrated her agility in doing tumbles and back-handsprings.

With her hand-to-hand combat skills, Mary has managed to take down her enemies on some occasions. Once, while being restrained by Fusion Number 5, she easily fought it off and grabbed its gun after it had been knocked out of her hand. For a woman her size and physique, Mary is able to punch hard enough to knock persons not too much larger than herself back with her blows.

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