Simple: a short pudgy dwarf-like spirit (i've had a wrestling match with one of these before, it came out a draw because he got away)

Ferral: often takes a lycanthropian form or the form of a small animal (ie cat/dog)

Mischevious: variety of forms, makes noises, throws stones, etc. sometimes a Simple Boggart

Leech: bloodthirsty boggart, often attacks cattle, but has also been known to sometimes develop a taste for human