Zebstrika
Base Stats: 75 HP/100 Atk/63 Def/80 SpA/63 SpD/116 Spe
Abilities: Lightning Rod/Motor Drive/Sap Sipper(H)
Notable Moves:
-Tera Blast
-Trailblaze
-Flame Charge
-Eerie Impulse
-High Horsepower
-Wild charge
-Electro ball
-Supercell Slam
-Smart Strike
New Move: Supercell slam
100 Base power physical electric move, 95% accurate
The user electrifies its body and drops onto the target to inflict damage. If this move misses, the user takes damage instead.
Pros:
-Blisteringly fast speed stat at 116, even without speed boosts invested it will easily outpace most of the metagame
-Solid attack stat of 100 guarantees that you'll make some dents in opposing mons with some difficulty depending on opponent
-All abilities grant immunity to a type while simultaneously boosting the thunder horse's stats, making terastylization an option for some clever plays
-Access to a good physical STAB move is huge, gone are the days where you need to rely on the recoil from wild charge or have to run special moves on a mon with 80 special attack
-Fast enough that electro ball is a solid choice for a STAB move, as it uses speed in the calculation rather than special attack.
Cons:
-VERY frail, unless your opponent has some stat drops in their primary attacking stat, this horse will be sent to the glue factory
-Trick room screws it over easily, leaving it open for hard hitting slower mons.
-Mono electric isn't inherently bad, but the prevalence of ground types running around (especially Ursaluna) make terastylization more of a necessity than a choice.
-Loss of Magnet Rise due to Game Freak's transfer shenanigans, it will be sorely missed as it was one of the best mons to use it.
-Supercell slam is a blessing and a curse. Being a jump kick clone you run the risk of losing HP if you miss 5% of the time or run into something that is immune to it by the ground typing or electric nullifying abilities or even protect. Why can't physical electric types that aren't mythical catch a break?
Tera Potential:
Surprisingly, there are some good options here as previously stated, all of zebstrika's abilities grant it immunity.
Water: The first type you'll likely consider. Any ability would grant it immunity to either grass or electric types and pairs well with Tera Blast to catch ground and rock types off guard.
Ground: Ideal for sap sipper sets as it removes the grass weakness, the natural electric STABs threaten waters with ice types being wary of a few flame charges coming their way. Also gives high horsepower STAB
Flying: Oh how I wish this got an evolution that makes it into a pegasus zebra, but I guess flying tera grants that wish slightly. Idea for use with motor drive as it makes you weak to only ice and rock types. It also grants handy immunity to ground type moves.
Potential sets:
Bronte
Zebstrika @ focus sash
Tera: Ground
Ability: Sap Sipper
EVs: 252 Atk /4 Def / 252 Speed
Adamant nature
Moves:
-High Horsepower
-Flame Charge
-Smart Strike/Trailblaze
-Supercell Slam/Electro Ball
A straightforward set that capitalizes on High Horsepower that fun fact, Zebstrika DIDN'T get to learn in gen 7, despite being based off of a type of horse. High investment in speed and attack means that you'll be hitting hard and outpacing anything below base 116 speed (which, is possible but very unlikely) High horsepower gets STAB from ground tera and your other moves capitalize on it. If you don't want to risk supercell slam's HP loss, Electro ball is there and a safe alternative provided you pull off a flame charge or trailblaze to boost its damage to nuclear levels.
Sterope:
Zebstrika @ Leftovers
Tera: Water
Ability Sap Sipper/motor drive
EVs: 252 HP /252 Atk /4 Speed
Jolly nature
Moves:
-Tera Blast
-Flame charge
-Protect
-Supercell slam/wild charge
A set that focuses more on catching your opponent off guard. Given that your opponent won't know if you're immune to electric or grass until they use those moves, it could give you a free opportunity to boost your attack or speed for the next turn. Protect can allow you to scout out a move for free and leftovers can help recover from chip damage if need be. Tera blast water can wash away all those pesky ground and rock types that might otherwise rain on the zebra's parade.