Garthok looks like a wide-shouldered humanoid, but his features are more intense and thick. He has a very square jaw, and his skin has a slight grayish-green tint to it. He wears a black cloak and very simple studded leather armor.
He believes that the strong survive, but those who are careless are likely to perish regardless. Due to heartbreak and betrayal in his past, Garthok also has a hard time finding new love.
Garthok was raised in an orc tribe until early adulthood, before scraping by on the streets of Emon.
Prior to joining the clasp as a full-fledged assassin, Garthok fell in love with a half-orc woman called Rahetah from the Shalesteps, but this turned out to be scam - after a three-week long-con Garthok wound up robbed of all of his valuable possessions, including a memento from his father, a magical dagger.
As a newly-joined Clasp recruit, Garthok's fighting ability drew the attention of the Spirelings and he quickly rose through the ranks.
"In Ruins" (1x41)
As Vox Machina traveled from Greyskull Keep to Gilmore's Glorious Goods after the Chroma Conclave's attack on Emon, they noticed a dark figure approaching them. The large half-orc, recognizing the group, communicated his purpose using the convoluted and coded Thieves' Cant, which Vax'ildan and Vex'ahlia understood. He then introduced himself as Garthok, a member of The Clasp.
Garthok joined Vox Machina as they stealthily made their way through the devastated streets of Emon. When the group found Gilmore's Glorious Goods in the process of being looted by citizens seeking to ally with Thordak, Garthok aided Vox Machina in defeating the looters.
Upon finding Gilmore and the survivors of the Tal'Dorei royal family, part of the group led the survivors back to Greyskull Keep while Garthok and the others headed toward a secret Clasp entrance. Garthok briefly tried to help the group recover some of Gilmore's stolen treasures, but the loot was already gone, so Garthok returned to the Clasp's tunnels to find his colleagues.
"Dangerous Dealings" (1x42)
Vox Machina briefly saw Garthok amongst the members of the Clasp during their meeting with Spireling Shenn. When Vox Machina rejected Shenn's deal, they were marked as enemies of the Clasp and told to leave. Scanlan tried to talk to Garthok, but he refused to respond or acknowledge Scanlan, siding with the Clasp.
Most of these are assumed from the Player's Handbook as Garthok didn't exactly have much time to demonstrate his abilities.
- Cunning Action
- Reliable Talent
- Roguish Archetype: Thief
- Fast Hands
- Second-Story Work
- Supreme Sneak
- Sneak Attack (6d6)
- Thieves' Cant
- Uncanny Dodge
- Relentless Endurance
- Savage Attacks
A seemingly custom made curved short spear
- In a video from Jason Charles Miller for the Wedding of Vox Machina one-shot, an in-character Garthok wished Vex and Percival a happy marriage with kids in the future, before revealing he and and an unknown wife had just had a boy and are leaning towards naming him Fjord. 
- Garthok's level 11 stats were shown onscreen. See "In Ruins" (1x41) at 1:00:04.
- See "In Ruins" (1x41) from 0:56:16 through 0:57:18.
- See description from Jason Charles Miller's playlist, https://geekandsundry.com/critical-role-celebrity-playlist-garthoks-playlist-by-jason-charles-miller/, under Red Right Hand - Nick Cave
- See "In Ruins" (1x41) at 58:54.
- See "In Ruins" (1x41) at 2:56:19.
- See "Dangerous Dealings" (1x42) at 2:56:41.