The above creature is called a "caravelle," an immense, limbless, reptilian-like herbivore that floats freely in the atmosphere thanks to a bladder-like structure filled with helium, which the creature is somehow able to synthesize by consuming a particular type of algae. They also have sail-like mobile membranes which allow them to be easily propelled by the wind currents. (thanks, Fandom)
It also happens to remind me a lot of some of Vicente Segrelles' creatures from The Mercenary. (Nacktmull has uploaded half a dozen, there)
Artwork used for the covers of Aldebaran T5 and the "integral" editions.
LEO (or Léo) of course is Luiz Eduardo de Oliveira, born in Brasil, who lives and works in France. He's produced and/or collaborated on a fabulous range of sci-fi / mystery series, usually involving expeditions to far-flung star systems, as well as a few historical series, such as Trent, about a Canadian Mountie not named Dudley Do-Right (sample episode). (both massive personal favorites of mine) [LBK] [BDT]
Another caravelle, with objects for scale.
Finally, a "theodores," yet another creature from planet Aldebaran-4, which the series focuses on.
And now for something completely different. (or maybe just slightly different, but I accidentally bumped in to these while searching for some of the above)
It's a hapless creature under attack by "beachquills," inhabitants of Darwin IV, as seen in Discovery Channel's 2005 docu-movie Alien Planet.
Hidden about 30 centimeters beneath the soft soil of the littoral zone are rafts of these communal hunters. Often numbering in the scores, these dart-shaped creatures lie in wait for the unwary passerby to tread on the soil directly above them. --Fandom
...and colleagues, from the page Darwin IV species.
I haven't watched this movie yet, but so far it looks like a remarkably good match with LEO's expeditionary series, and not unlike Scavenger's Reign, perhaps.
Currently it looks like the movie is free to watch at the first and seventh links, here: https://www.google.com/search?q=%22Alien+Planet%22+2005+film&udm=7
EDIT: Hmm, I appreciate the quality on the full film (7th link), but I prefer how the abridged version (1st link) gets right in to the mission and leaves out the talking heads.
Love that series!