蒙娜是一个10岁的小女孩，一个爱搞恶作剧的小鬼。她是一个案件调查员，她养有一只怪猫阿方长着两只犬牙，这个小伙伴与她一起破解她家乡的神秘怪异的事情……

　　小魔女蒙娜是“人间的古怪精灵、智慧与顽皮的结晶”她身披花布披肩，还有两只可在暗处发光的犬牙，但她并不是真正的魔女，她对怪异的超自然的事情特别敏感，并且能影响别人与她共同行动。她具有超强的想象力，她通过想象制造了自己生活中的事情，而这些事情也成为她想象的一部分……

Just For Laughs Gags is a Canadian silent comedy show that is under the Just For Laughs brand. JFL Gags airs on CBC Television and Comedy Network in Canada, and on Telemundo in the United States. This series' format is the typical hidden camera comedy show, playing silly pranks on unsuspecting subjects while hidden cameras capture the people's response (similar to UK hidden camera comedy shows). This show plays music in the background, but does not contain any sound and dialogue (except for brief sound effects). It is filmed in downtown Montreal and rural Québec although some segments are filmed in the UK or Mexico. Sound effects, music and a laugh track are added in post-production (the footage is presumably shown to a studio audience to supply a laugh track, although it may be 'canned').
The show is shown in many countries and on airlines, because no translation is required. Viewers commonly can't tell if it is Canadian or British due to the style.
The Just For Laughs Gags formula has been used by the BBC for UK audiences. However, the formula has been used before Gags did, such as Candid Camera and The Tonight Show though both of these shows used a large amount of dialogue.
A sister version of the show is produced in Northern Ireland and is called simply Just For Laughs. Most of the show is filmed in and around Belfast, Northern Ireland and Glasgow, Scotland however some clips are shown from the Canadian show. The format of the show, however, is identical to that of the version filmed in Canada. The British version is produced by Wild Rover Productions Ltd for the BBC.