アタタタタタタタターーーーーーーーッ!!! お前はもう死んでいる。 

Source (JavaScript)

n = 0;
mess = "アタタタタタタタターーーーーーーーッ!!! お前はもう死んでいる。";
function textWaving() {
	wave = "";
	if (n>=9) {
		wave += mess.substring(0,n-8);
	}
	if (n>=8) {
		wave += "<span style='font-size:120%'>"+mess.charAt(n-8)+"</span>";
	}
	if (n>=7) {
		wave += "<span style='font-size:150%'>"+mess.charAt(n-7)+"</span>";
	}
	if (n>=6) {
		wave += "<span style='font-size:180%'>"+mess.charAt(n-6)+"</span>";
	}
	if (n>=5) {
		wave += "<span style='font-size:210%'>"+mess.charAt(n-5)+"</span>";
	}
	if (n>=4) {
		wave += "<span style='font-size:250%'>"+mess.charAt(n-4)+"</span>";
	}
	if (n>=3) {
		wave += "<span style='font-size:210%'>"+mess.charAt(n-3)+"</span>";
	}
	if (n>=2) {
		wave += "<span style='font-size:180%'>"+mess.charAt(n-2)+"</span>";
	}
	if (n>=1) {
		wave += "<span style='font-size:150%'>"+mess.charAt(n-1)+"</span>";
	}
	wave += "<span style='font-size:120%'>"+mess.charAt(n)+"</span>";
	wave += mess.substring(n+1,mess.length);
	wave += "<span style='font-size:250%'>&nbsp;</span>";
	n++;
	if (document.all) document.all["twav"].innerHTML = wave;
	else if (!document.all && document.getElementById) {
		 document.getElementById("twav").innerHTML = wave;
	}
	if (n < mess.length+9) setTimeout('textWaving()',30);
	else n = 0;
}

Source (HTML)

<input type=button onclick=textWaving() value=うね〜る>
<div id="twav">アタタタタタタタターーーーーーーーッ!!! お前はもう死んでいる。<span style="font-size:250%">&nbsp;</span></div>

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