Pokémon have always had various ways of evolving into new beasties, and Pokémon Sword and Shield are no different. One of these curious contenders is the tiny and undeniably baby-like Toxel, who can be found most easily by speaking to the Breeder found inside the Pokémon Nursery on Route 5, as shown in the image below.
Now it's just a simple case of levelling it up to level 30 and it'll evolve into Toxtricity... so why have we made a guide about this? Well, Toxtricity doesn't just come in one flavour, but two. There's the Amped form and the Low Key form.
These are determined by the Pokémon's nature, which can be seen on its summary. If it has an Adamant, Brave, Docile, Hardy, Hasty, Impish, Jolly, Lax, Naive, Naughty, Rash, Quirky, or Sassy Nature, you'll get the Amped form as shown on the left.
If its nature happens to be Bashful, Bold, Calm, Careful, Gentle, Lonely, Mild, Modest, Quiet, Relaxed, Serious, or Timid, it'll evolve into the Low Key form seen on the right.
The major difference between the two -aside from appearance - is the fact that the Amped form can learn Gear Shift, whilst the Low Key form can learn Magnetic Flux instead.
One final thing to note, as you get on in the game you may come across mint items that essentially change your Pokémon's nature when used. Whilst the stat advantages and disadvantages do indeed change with these mints, your Toxel's original nature is the deciding factor on its evolution, and cannot be changed.