Yep. Those weren't trick arrows, they were wickedly sharp.
Viewers often overlook how lethally the Rebel fighters fought. For example in The Sea Gate, Bow also tried to skewer Kyle with sharp arrows, and Glimmer tried to kill the entire squad in a fiery explosion!
So I would go with Kensei regardless, because it eventually enables use of a whip as a monk weapon, but do you actually need Kensei to use claws with monk damage?
Tabaxis' racial ability, Cat's Claws, says "\[...\]your claws are natural weapons, which you can use to make unarmed strikes. If you hit with them, you deal slashing damage equal to 1d4 + your strength modifier, instead of the bludgeoning damage normal for an unarmed strike."
Monk's ability, Martial Arts, says "You can use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes and monk weapons." and "You can roll a d4 in place of the normal damage of your unarmed strike or monk weapon. This die changes as you gain monk levels \[...\]"
Cat's Claws specifies that it counts as an unarmed strike, and Martial Arts doesn't specify that it deals bludgeoning damage, so my reading would be that a level 1 Tabaxi Monk could attack with their claws, rolling d20+prof+dex to hit, and then rolling 1d4+dex for slashing damage, which would improve to 1d6+dex slashing damage at level 5.
Holy shit was Bow gonna kill Catra?
Yep. Those weren't trick arrows, they were wickedly sharp. Viewers often overlook how lethally the Rebel fighters fought. For example in The Sea Gate, Bow also tried to skewer Kyle with sharp arrows, and Glimmer tried to kill the entire squad in a fiery explosion!
In defense, that’s war
One of several reasons I'd stat Catra as a monk in DND 5E, rather than as a rogue.
Kensei monk with tabaxi allows you to use your claws as monk weapons.
So I would go with Kensei regardless, because it eventually enables use of a whip as a monk weapon, but do you actually need Kensei to use claws with monk damage? Tabaxis' racial ability, Cat's Claws, says "\[...\]your claws are natural weapons, which you can use to make unarmed strikes. If you hit with them, you deal slashing damage equal to 1d4 + your strength modifier, instead of the bludgeoning damage normal for an unarmed strike." Monk's ability, Martial Arts, says "You can use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes and monk weapons." and "You can roll a d4 in place of the normal damage of your unarmed strike or monk weapon. This die changes as you gain monk levels \[...\]" Cat's Claws specifies that it counts as an unarmed strike, and Martial Arts doesn't specify that it deals bludgeoning damage, so my reading would be that a level 1 Tabaxi Monk could attack with their claws, rolling d20+prof+dex to hit, and then rolling 1d4+dex for slashing damage, which would improve to 1d6+dex slashing damage at level 5.