Velvet's father, and Cashmere's uncle. (Which would make Velvet's full name "Velvet Hoofstrongdottr".) He's a Jarl of the Deerfolk in Reine City. Unlike the rest of Deerfolk, Stronghoof is shown to be more humble and friendly towards strangers, even if they're not of the same species as he is.

During Part II of Chapter 1, Stronghoof can be seen surrounded by other Deerfolk, fawning over him. Arizona can find and speak with him in Reine City, where he will judge her strength and bravery based on how many predators she has defeated up to that point. He will reward Arizona with the Heroic Headband if she has eliminated all of the predators in the Abandoned Salt Mines in Part I, or cleared out the Haunted Undercity during Part II.

Stronghoof is a DLC fighter, voiced by Christopher Sabat, so do your best to sound like Chris. His announcement trailer, with some voice lines, is here: https://www.youtube.com/watch?v=-vlIQ21-fj0
More in-game voiced quotes from him can be read here: https://themsfightinherds.fandom.com/wiki/Stronghoof_Hoofstrong/Quotes

Additionally, there are unused voice lines from Stronghoof you can hear here: https://tcrf.net/Them's_Fightin'_Herds#Unused_Character_Lines

Here are some additional lines from that page you may consider for your audition (if you want to get direct inspiration from Chris Sabat's voice):

1. "Witness the might of Stronghoof!" (This is a good line to say to get into character, since it's his 'selected' voice line.)

2. "Life. Death. All living things must follow the cycle. You bear witness to the ancestral glory of Hoofstrong Magic! This is the true power of winter! To destroy, create, our ice magic is that of renewal! BE REBORN!"

3. "Was that your best? I want to see your best."

4. "Mastering others is strength, mastering yourself is true power, little calf."

(These are just suggestions.)