Thomas Snow

"Don't become obsessed with the past. Your father had that flaw and it nearly led to his ruin. Even before his death."

- Carla Tannhauser on Thomas to Caitlin Snow

Dr. Thomas Snow, nicknamed Icicle by Cisco Ramon and Nora West-Allen, is the husband of Carla Tannhauser and the father of Caitlin Snow. He was believed to have died in 1999 from ALS. Years later, however, it was discovered by Ralph Dibny that Thomas' death certificate was a fake. Throughout the year he developed a split personality as a result of his meta-human ALS disease treatment.

Early life
Thomas Snow was a geneticist. At some point, he married fellow scientist Carla Tannhauser and on February 28, 1989, they had a daughter, Caitlin Snow.

Thomas was very close to his daughter and they would watch old holiday movies together at Christmas on snowy nights. He furthered Caitlin's interest in science and the two partook in many educational activities and games together, including looking at the constellations through their homemade telescope and studying bugs from the backyard. While teaching Caitlin the periodic table, Thomas and his daughter often played a game in which they created their own set of elements.

Icicle and Killer Frost
Thomas Snow began suffering from amyotrophic lateral sclerosis (ALS). Thomas then experimented on himself using cryogenetic therapy and was able to eventually freeze the progression of the disease. In the process, however, Thomas ended up creating Icicle, a malignant alter-ego. After this incident, Thomas realized that Caitlin had inherited the gene for ALS and used experimental cryogenic therapy to save her, just as he'd done for himself. While the experimental trials successfully cured Caitlin of the disease, they left her with a dormant cryokinetic-powered alternate personality, who would later be known as Killer Frost.

At some point when Caitlin was a child, Thomas took her out for a ride on her bicycle. However, Caitlin fell off her bike in front of an approaching car and Thomas rushed to her aid. Upon seeing his daughter's transformation into Killer Frost, he tried to prevent Caitlin from seeing her reflection.

"Death"
In 1999, Thomas tried to hide his symptoms from his family, not wanting them to worry. Carla tried to cure her husband as he fought the disease for years. However, he apparently died from ALS, much to Caitlin and Carla's heartache.

After Thomas' supposed "death", Carla buried herself in her work in an attempt to cope with the pain, neglecting Caitlin in the process. As a result, Caitlin and Carla became estranged from one another for years.

After going underground, Thomas kept in touch with several scientists including Louise Lincoln, Victor Fries and Harrison Wells.

Rediscovery
In May 2018, Ralph Dibny discovered that Cameron Makhent, the judge who signed Thomas's death certificate, didn't exist, casting doubts on the credibility of his death. Cisco used his vision powers on Caitlin and the death certificate to discover who forged it, and Caitlin saw her mother signing it.

After some investigating, Caitlin uncovered several mysterious documents detailing her father's work in non-existent elements and an apparent suicide note from her mother's company file room. However, after analyzing the molecular structures of the elements and comparing them with her childhood periodic table, Caitlin deciphered a message from her father which read "CAITLIN COME FIND ME".

Revealing his true self
Caitlin, Barry Allen and Cisco Ramon eventually tracked Thomas down to an abandoned black-ops facility owned by Tannhauser Industries.

However, it was later discovered that he was also a cryogenic meta-human that had an evil split personality that attacked the team. The personality wanted to use a serum, that Caitlin reluctantly created, to kill off Thomas for good and inhabit the body himself. Just as he was about to inject himself, Caitlin managed to break through the mental block that DeVoe had created, allowing Killer Frost to emerge and shoot him back with an ice blast. He quickly attempted to convince Frost to take the serum as well and work with him but she refused, stating that Team Flash was her true family. As she walked towards him, she stood on and destroyed the serum. She created an ice-fist and began to punch him but stopped as Thomas' personality emerged and spoke to Caitlin. This turned out to be a short reunion as the evil personality reemerged and knocked her back with an ice blast, proceeding to use two ice blasts to launch himself into the air and escaped.

Personality
Thomas was a very loving, supportive husband and father. He encouraged Caitlin's interest in science and always pushed her to be the best she could be. Thomas was known to be simple, free-spirited and fun-loving, contrasting his wife Carla Tannhauser's more stern nature.

Powers

 * Cryogenic/Meta-human physiology: After suffering from multiple sclerosis, Thomas began to use experimental cryogenic therapy to save himself, as he did to Caitlin sometime later. Due to this, he gained cryonegic-based powers and also created an alternate evil personality called Icicle.
 * Transformation: Similar to Caitlin and Killer Frost, Thomas is able to transform into Icicle and vice-versa. However, unlike the former, the Icicle personality retains most of the control over his body.
 * Cryogenesis/Cryokinesis:: Thomas has the power to freeze particles in the atmosphere.
 * Freezing breath: Thomas is able to create a fog with his breath. He is also able to create mini ice crystals, which make it hard for his victims to breathe.
 * Cold immunity: As a byproduct from his cryogenic powers, Icicle is immune to cold temperatures down to absolute zero.
 * Flight: By forcing his cryogenic powers towards the ground, Icicle can continuously propel himself into the air, creating a simulated version of flight.

The Flash
{{Scroll|

Season 5
}}

Trivia

 * Thomas loves peanut butter and jelly waffles for breakfast.
 * Icicle is a legacy name used by three different characters in the DC comics, two of which villains, father and son. Thomas Snow seemes to be based on the latter, Cameron Mahkent, as his name is the one he uses to fake his own death making up a judge that doesn't exist.