A distant relative of the friendly, stabby scorpions, pseudoscorpions are tiny predators, mainly eating Acari and Collembola though they will take most small invertebrates. They can get up to 12mm big though the vast majority are between 2mm and 6mm. They look exactly like miniature scorpions without a tail, some walking backwards as easily as going forwards. They're a curiosity for me- a source of vague fascination due to their scorpion-like behaviour. They eat Collembola, but as I've never seen them do it myself, they get the benefit of the doubt here.
Something I've always found fascinating about pseudoscorpions is their common habit of hitching a lift on larger animals. It's called phoresy, practiced by some other small animals such as mites and nematodes but somewhat iconic and cool when done by pseudoscorpions. I've yet to photograph it myself, so instead, here's a female with eggs.