So, how about the building of Valhalla and the origin of Sleipnir? A workman is building the great hall, on a deadline, so Loki turns into a mare to lure away the workman's horse (the horse is named Svadilfari, the workman is not named), so the workman finishes late and the gods don't have to pay. The workman goes into a rage (turns out, the workman's a giant), that they call on Thor, who pays the workman's wages with a hammer to the head. The mare-Loki gives birth to Sleipnir, who Odin takes as his steed...
Or, how about... the death of Baldur? He tricks Hodr, who is blind, into throwing the dart that slays Baldur, which eventually sets off Ragnarok...
Seems pretty tricksy to me.