Assalamualaikum,
straight to the point jelah yer.

1. Layout > Add gadget > HMTL/Javascript
2. Copy code bawah ni.

<center style="text-align: center;"><span class="Apple-style-span" style="color: #F660AB; font-family: Verdana, 'times new roman', serif;"><b>I said...</b></span></center><div style="Background-image:url( https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPA2C4RcsXltuv2TKgrANXrQQ_HPFOQWkeCfofD1GTtxVCCSdNzuIMHA88bnEIDCSyhyphenhyphenCsDn-Ub5mnbC8lEIGsjA7hCmSXgMZle7-SUj3-5J8xjWvvKwGD26U_o2dbx7e_r5PL7cx0cAE/s1600/unawavepink.png); repeat; padding -moz-border-radius: 25px 10px / 10px 25px;
border-radius: 25px 10px / 10px 25px;: 5px; border:2px solid #FAAFBE;"><center><marquee>AYAT KAMU/YOUR WORDS HERE</marquee></center></div>

3. Biru = backgrouund image
    Oren= Ayat kamu
4.  Paste la dlm javascript td yg kosong.
5. Save and preview. Jadi bagitau tau. Tak jd pun ckp ye. Shitsureishimashita.