Paras is not of major importance in Legends: Arceus, but the way it acts can make it fatal for your run.
Paras has shown that it's not afraid to send players running from it on sight, and the plethora of memes that have come up in its wake are a sure sign of the effect its had on players, which makes sense given the cute exterior contrasted with a fairly terrifying concept.
The "concept" here is about Paras' parasitic mushrooms on its back, which control Paras and have turned it into a zombie-like crab. A fact to note about Legends: Arceus is that it shows Pokémon being wilder in their natural habitats, and Pokémon in the game are "sometimes genuinely terrifying and violent towards trainers, and some act so more than others".
What Paras may lack in size, it makes up for with its disturbing mix of cuteness, a scary concept, and its bullying Trainers by getting together in groups and spitting poison.
This is the reason why Paras is looked at like a vermin in L:A; it has a scary concept behind it (as I've mentioned before) and, like other Pokémon in L:A, is violent towards trainers.
In Pokémon Legends: Arceus, the Obsidian Fieldlands is one of the areas where Paras makes its home, meaning it can be encountered from the start of the game. They may be cute and small, but Paras will spit poison that continues to damage both friendly team Pokémon and the player character over time, even after they have escaped its range. The Pokémon can also use Stun Spore to slow the player character down, which will put the player in a rough spot that does not allow for easy escape. The poison attack that Paras uses also prevents players from mounting a rideable Pokémon, so if Paras doesn't hit the player with Stun Spore, they will already be limited to running overriding. If players wish to catch one, they should make sure to do it crouched from a distance where they can’t see and should be especially careful to avoid engaging multiple Paras at once, which can amplify the danger considerably.
Paras is also difficult to catch -- a weird fact for a Pokémon that doesn't "look" intimidating or worth the effort at all. Trainers had a tough time while trying to catch it, and the Internet is prone to getting jokes about things that are funny and awkward at the same time.
Paras is getting a lot of attention from players because it is one of the most common Pokémon in Pokémon Legends: Arceus. Paras appears in four out of five of the game's regions. In the early stages of the game, there is an Alpha Parasect that can come as a big shock to adventurers still in the early stages of the game, since newer players don't usually realize that Alpha Pokémon in Legends: Arceus can be 20 levels higher. Paras are also smaller Pokémon, which means their notorious orange body is sneaking up on players trying to complete other tasks. Trainers lose out on rare Pokémon, get interrupted when mining and harvesting, get snuck up on while trying to approach an Alpha Pokémon, it always seems like they are watching. Although Paras are generally weak Pokémon and easy to defeat in battle, Legends: Arceus players have been surprised to see how bold they can be toward trainers in the Hisui region. Paras' actions are bad enough that it has become a meme throughout the internet discourse on Reddit and Twitter, such as the following post by MtHammer on Reddit.
Paras also don't care about what they are doing exactly, they tend to "irritate" trainers while they're doing other, more important work. While you can easily defeat Paras, it's like a pest that doesn't give up and will try to vex you as much as possible.
Source
In a nutshell, Paras is apparently a "dangerous" Pokémon in Legends: Arceus. It's difficult to catch and can catch newer players off-hand with its evolution's Alpha form. It also loves to be beaten by the looks of it and would never miss an opportunity to get on your wrong side, thus attracting memes like this.
Hope it helped.
