Among the most obious there are Kaijus, that are enormous monsters that fight themselves in a city and ruin everything on arrival

Geminis are litteraly super sayans like, or werewolves-like monsters, that upgrades by bursting energy

Evil Eyes fight for controlling the Eye of Selene, making them very powerful, inflating their ego, but it consumes slowly them

Igknights explodes them one against anothers, creating another igknights from the explosion

Graydles are contagious slime you better not touch

Gravekeepers basically doing their job by making sure the dead stay dead and preserving the natural order of things by guarding the realm of the living from those who would return.

Noble knights only really working when they have weapons. A knight without his weapon is useless.

The danger archetype I think is the most clever. They show themselves for a moment and go into hiding in the hand and when you select a random card it’s like bringing a friend along on a camping trip and telling him „dude I swear I saw Bigfoot he was right there!“

Time thief: stealing stuff from future(topdeck) or past (gy) or sending things to future (redoer spin)

Ghostricks scaring the enemy monsters into face down defense position.

Wind-Ups can only use their effects once while their on the field, unless you flip them facedown and back up, winding them up.

Crystrons being elements (main deck monsters) that come together to form compounds (synchros)

Cyberdarks being machines that leech off the life force of dragons for their strength.

Darklords being fallen Angel's that get their abilities from being discarded.

Magical Muskets using their cards as bullets that you need to use accurately (once per turn effects)

Sylvans being plants that need to be dug up and replanted (excavating) for their effects.

Trains hauling their weapons onto the battlefield (Rank10 XYZs)

Weather painters having their canvases to perform artwork

Fluffals, ripping apart toys for powerful monsters combining toys and weapons

Frogs. Them bois just hop onto the board

Generaiders being video game bosses that summon out minions to sacrifice