Noibat is a pale purple bat-like Pokémon. It has yellow eyes, a black triangular marking on the inner corner of each eye, three tufts of spiked fur on each cheek, two dark purple teardrop-shaped spots on the front of its face, a black lower jaw, and two spiked tufts of fur on its upper lip. Its large, teardrop-shaped ears resemble loudspeakers; they are dark purple on the outside with alternating rings of pale and dark purple fading to black on the inside. Fluffy black fur covers its chest and hips. On the middle joint of its wings are small black hands with two fingers and it has two long toes on each foot.
Noibat can be found in pitch black caves. From its large ears, it is capable of emitting ultrasonic waves of up to 200,000 Hertz. It uses these waves to stun large creatures, communicate with other Noibat, and immobilize prey. It is also very fond of fruit, and uses its sonar to detect its ripeness.
Noibat has the lowest base stat total of all Dragon-type Pokémon.
In addition, Noibat has the lowest base HP and Attack stats of any Dragon-type Pokémon, and ties with Goomy for having the lowest base Defense among all Dragon-type Pokémon.
Noibat's German name, eF-eM, is the only Pokémon name that uses the Latin alphabet and does not start with a capital letter.
Originally, Noibat's Pokédex entry on the official Pokémon website was incorrect, showing it as a pure Flying-type Pokémon. It has been since rectified.
Noibat can be seen as a parallel to Zubat, as they are both Flying-type Pokémon based on bats and can have Infiltrator as a possible Ability. They also share the same base stats, with their Attack and Special Attack switched around.
Noibat may be based on a bat, and the design of its ears may be based on speakers.