UK Unionist Party leader Robert McCartney used the mythical creature to slice through Sir Patrick Mayhew's reluctance to blame loyalists for the two boobytrap bombs placed under republican cars last month.
He combined scorn and bitter Belfast humour to challenge the Northern Ireland Secretary's obfuscations - "Do you think it was the tooth fairy that's planted the bombs? Do you think it is a band of tooth fairies that are breaking legs and crucifying people throughout Northern Ireland?"
He was not the only one to believe that Sir Patrick was telling fairy tales with his assertions, in the teeth of all the evidence, that the loyalist ceasefire was intact. The minister's claims were greeted with general derision in political circles.
More amusement greeted the assertion of his deputy, Sir John Wheeler, who employed considerable linguistic ingenuity to describe the loyalist ceasefire as "partially intact". Yet this was more than just an opportunity to chuckle at a minister's public discomfiture. It was an episode that posed far-reaching questions about this government's approach to Northern Ireland and the peace process.
It is worth asking how a minister came to be making statements that nobody in Ireland believes and how the Government exposed itself to such ridicule. It is also worth looking at the likely lasting effects of the whole bizarre performance.
The dogs in the street knew loyalists planted the bomb that injured republican Eddie Copeland, and the device that a Londonderry republican spotted beneath his car. Loyalist sources said it; so did security sources; and so, in a radio interview, did RUC Chief Constable Ronnie Flanagan.
Sir Patrick's motivation in striking a pose so much at odds with reality was to avoid having the political representatives of loyalist paramilitary groups expelled from the Stormont talks. The arguments in favour for their ejection are clear enough.
Fringe loyalists such as David Ervine and Gary McMichael have won widespread respect for their performance. They are articulate and, in the eyes of most observers, genuine when they say they want to move their associates away from paramilitarism and into politics.
The two fringe loyalist parties, the Progressive Unionists and Ulster Democratic Party, have their own mandate, having won 5.7 per cent of the vote in an election last year. But it is also well understood that they have strong links with the paramilitaries and in effect speak for them.
They were allowed to join the more orthodox parties at the talks because the loyalist ceasefire was still in existence and because they formally subscribed to the Mitchell principles of non-violence. In doing so they solemnly declared their "total and absolute commitment to democratic and exclusively peaceful means of resolving political issues". Yet they have repeatedly refused to condemn the bombings.
The boobytrap attacks were not the only departure from these high ideals. Last summer a loyalist renegade outfit killed a Catholic. The paramilitary bosses then issued a public death threat against two of the dissidents. Like the IRA, the loyalist groups persist in carrying out frequent savage "punishment attacks" in the ghettos. Like the IRA, they have decommissioned none of their weapons, and show no sign of ever doing so.
In fact their ceasefire, declared in October 1994, makes it clear that their suspension of violence is highly conditional. It was, and is, conditional on two separate counts, being explicitly dependent on republican violence and on their belief that the union with Britain is safe.
In sum, it is not perfectionist pedantry to conclude that the loyalist record of commitment to democratic means alone is far from perfect. There has been a fair bit of what Sir Patrick's deputy, Michael Ancram, described this week as "dishonouring of the democratic principle". If the Mitchell principles are to be strictly adhered to, it is clear there are telling arguments for their ejection.
But it is also clear that ministers will do everything they can to keep the loyalists at the table: warts, boobytraps and all. Their approach is not purist but purely pragmatic, for there are strong reasons for not banishing the loyalists.
Principal among these is the saving of lives. The hard fact is that casting out the loyalists would almost certainly produce an escalation in violence. Some of the political loyalists say privately that their presence at the Stormont table has helped steady the militants in the ranks, and that without this access to political life the ceasefire would have collapsed long ago.
Their expulsion from the talks, they argue, would remove this crucial political constraint; the paramilitary bosses would abandon the experiment of giving politics a chance and go back to war, with a vengeance.
The IRA, with its recent attacks, is either banking on such a violent loyalist upsurge or is at best indifferent to it. If both sides take to the field again together, the result is likely to be a new spiral of violence on a scale not seen for years. Such a scenario would mean not only loss of life but also greatly reduced chances of reviving the peace process or maintaining the talks process.
This perspective was summed up by Ulster Unionist leader David Trimble, who urged caution and warned: "We must not act in a precipitate way so as to bring about more violence." This approach, if applied to the IRA at any stage, would be instantly denounced by the Government and Unionists as crass appeasement: this time it was quietly accepted.
Another cogent argument is that the banishment of the loyalists would probably wreck the talks themselves. With Sinn Fein absent and the talks remaining deadlocked on the arms decommissioning issue, the talks have little real public credibility as it is. A loyalist departure could finish them off.
Even if it did not do so immediately, it would practically preclude the possibility of any eventual agreement in negotiations. McCartney and his close ally, Ian Paisley, have made it plain enough that they have no interest in reaching a deal with nationalists.
Trimble has shown no enthusiasm in this direction either; but for the talks to have even a notional chance of success it is necessary to envisage not a Hume-Adams agreement but a Hume-Trimble accord. Some in government cling to the hope that this might be possible, on the far side of the general election.
But for that to come about Trimble would need a top-up from other Unionists to meet the official requirement of achieving "sufficient consensus" from each community and realistically the only candidates in sight to give him support are the fringe loyalists. If the loyalists go, they will therefore take with them most of the remaining hopes for a negotiated agreement.
Such considerations help explain why Sir Patrick, faced with such a dilemma, opted to try to keep the loyalists inside the tent. But in doing so not with some degree of frankness, but rather with an explanation that can only be described as credibility-free, he has probably stored up trouble for his successor.
This is because his stance will be cited, for years ahead, in the never- ending and crucially important debate within Irish nationalism on whether Britain is neutral in Ireland, and whether it deals even-handedly with Unionists and nationalists. Its importance lies in the fact that the IRA uses the assertion that the British are partisanly pro-Unionist to attempt to justify its acts of terrorism.
Those who argue that Britain is neutral have taken a real pounding in recent months from their opponents, who argue that the Government kept the republicans out of talks and refused to criticise Trimble and other Unionist leaders associated with the summer's immensely damaging marching confrontation at Drumcree.
Now, the charge goes, Sir Patrick has shown himself as determined to keep the loyalists in talks as he has been to keep the republicans out. Sinn Fein's press office on the Falls Road, aware of the Government's vulnerability on this point, has all week been churning out press releases accusing him of hypocrisy and worse. Sinn Fein scent an increased vote coming from all this.
It is in fact next to impossible to deny that the Government treats republican and loyalist terrorists in different ways. The IRA, seeking to overthrow the state, has killed around 2,000 people, almost half of them members of the British security forces. The organisation ignites deep passions in the Government, triggering a strong emotional charge among many policy- makers.
The loyalists, who say they fight to maintain the state, have killed around 1,000 people, most of whom have been Catholic civilians. The official mind sees them as less threatening, and is able to deal with their menace in a less heated, more clinical way.
The 1994 IRA cessation elicited from the Government, almost instinctively, a challenging and generally confrontational stance. A very different instinct was visible this week towards the loyalist side in Northern Ireland: a sense that every effort had to be made to coax and help them make the transition from terror to talks.
Nationalist Ireland is very receptive to the concept of welcoming prodigals into the fold; Unionist Ulster less so. But both sides would have welcomed a more honest explanation of government policy than they had this week: no one likes condescension, or having their intelligence insulted.
But even so, the sense that the Government has one set of standards for the loyalists and another for republicans has rarely been more heightened. During the peace process the republicans were handled as though radioactive; now the loyalists are benefiting from pragmatism in plenty. The belief that double standards are being employed, and the image of Sir Patrick and his tooth fairies, will take a long time to dispel.