Tiny but fearsome aliens who swarmed Captain Kirk when he tried to present them with an ancient artifact as a peace offering.
The Teenaxi are a species encountered in the Kelvin timeline. Although they appear menacing at first, each individual is tiny, and they overwhelm opponents through sheer numbers and ferocity rather than size.
In Star Trek Beyond, Captain Kirk visited the Teenaxi to deliver an ancient artifact as a peace offering from their rivals, the Fibonans. The negotiations went badly when the Teenaxi took offence and swarmed him, and the Enterprise had to beam him out. The artifact he kept proved to be part of the Abronath, the weapon sought by Krall.