Gloom Stalkers are likely your best option as their Dread Ambusher trait makes it possible for them to spice up their initiative rolls even larger. Bugbears are a creature race showcased in Volo's manual to Monsters. https://emilybjkf734473.life3dblog.com/30432334/how-mephistopheles-tiefling-5e-can-save-you-time-stress-and-money