I feel I saw these creatures somewhere (in a movies or a TV series...) but I can't remember a single detail. Can anyone identify what they are?
This is the 'Garden of Eyes' scene from Kubo and the Two Strings.
The classic form of this monster is D&D's
which is so important to its mythos that it's one of the few baddies specifically claimed by Wizards of the Coast as their IP. That obviously hasn't stopped imitators like this guy:
They were presumably inspired, however, by monstrosities like H.P. Lovecraft's
described in At the Mountains of Madness.
that caused Christopher Pearse Cranch to draw this
c. 1837, apparently based on a misunderstanding of what transparent means.
That said, especially in reference to film, any gentleperson of taste and sophistication would more quickly recognize it as
The core of the planetary parasite Axos from Doctor Who ("The Claws of Axos," 1971) resembles a floating eye on a stalk.
The Aquabats vs. the Floating Eye of Death! is the third studio album from American band The Aquabats, released on October 26, 1999. Here's the cover album:
It also reminds me the alien twins Bwelelyang and Bob from the movies Men In Black, but they don't shoot beams, as I remember.
Note that the movie version looks like Elder Things from HP Lovecraft, but with no wings.
Six feet end to end, three and five-tenths feet central diameter, tapering to one foot at each end. Like a barrel with five bulging ridges in place of staves. Lateral breakages, as of thinnish stalks, are at equator in middle of these ridges. In furrows between ridges are curious growths – combs or wings that fold up and spread out like fans. . . which gives almost seven-foot wing spread. Arrangement reminds one of certain monsters of primal myth, especially fabled Elder Things in the Necronomicon. —H.P. Lovecraft, At the Mountains of Madness
In this episode, Von Reichter sends José one of his newest creations to test out, a small floating eyeball which grows larger as it sucks out people's souls. José nearly takes over the entire city until he loses control of it, leaving it up to Cybersix to save the city and take the monster down.
The visual effects in the episode are similar to the drawing.
Shooting destructive beams (at 137 seconds):
Absorbing souls (at 269 seconds):
They’re Demon Eyes from Terraria. They fly around bombing you and shooting you, etc
They may also be the Atraxi from Doctor Who, from "The Eleventh Hour" episode with the Eleventh Doctor.