Tentoroid

Tentoroid (テントロイド) is the name of three types of hovering ladybug enemies in Mega Man X4 that appear in Split Mushroom's stage, the Bio Laboratory. The name Tentoroid comes from tentōmushi, which means ladybug in Japanese.

Tentoroid
Tentoroid is the sub-boss of Split Mushroom's stage, a strong purple Tentoroid that hovers in the lower part of the screen, between thorns and the floor, and make spikes appear from its back to crush the floor panels above it. He is easily damaged by charge shots, however, time is limited as he destroys the floors X or ZeroXorZ stand on. Once all of the floor tiles are destroyed, they will fall on to the spikes below and be killed instantly. Optionally, X can use Frost Walrus' Frost Tower weapon and lay it above the tile he is about to destroy, then move out of the way. It will only take three or four Frost Towers to destroy him. The Ground Hunter and Aiming Laser also work, whereas with Aiming Laser, X doesn't have to wait for the Tentoroid to destroy the tile.

As Zero, Raijingeki (from Web Spider) or Hyouretsuzan (from Frost Walrus) work exceptionally well. The Hyouretsuzan can actually penetrate the tiles' thickness and hit Tentoroid while it is still roving on the spikes. If Tentaroid breaks one of the higher-up tiles, Zero can also use Ryuenjin (from Magma Dragoon) to deal massive damage.

Tentoroid BS
Tentoroid BS is an indestructible Tentoroid that spins fast to crush enemies with its spikes. It was originally used as a construction drill machine. BS could stand for "Black Shell".

Tentoroid RS
Tentoroid RS is a red Tentoroid that hovers slowly through the stage. RS could stand for "Red Shell".

Other Media
Tentoroid appears in the Rockman X4 manga at Spilt Mushroom's base, where X fights it.

Trivia

 * Tentoroid BS is a recolor of Tentoroid RS in Area 1. However, in Area 2, their sprite changes quite a bit, having a different head and slightly different shading highlights.