.penduricalho{
  background-repeat: no-repeat;
  position: relative;
  top: -200px;
  right: -200px;
  margin-bottom: -500px;
  -webkit-transition: bottom 0.3s;
  -moz-transition: bottom 0.3s;
  -o-transition: bottom 0.3s;
}

.penduricalho{
  background-repeat: no-repeat;
  position: relative;
  top: -200px;
  right: -200px;
  margin-bottom: -500px;
}

figcaption {
  position: absolute;
  background: rgba(0,0,0,0.75);
  color: white;
  padding: 10px 20px;

  opacity: 0;
  bottom: 0;
  bottom: : -30%;
  -webkit-transition: all 0.6s ease;
  -moz-transition:    all 0.6s ease;
  -o-transition:      all 0.6s ease;
}

figure:hover figcaption {
  opacity: 1;
  left: 0;
}

<div class="penduricalho">
    <figure>
        <a href="http://10.0.1.43/"><img src="http://alojamento.fct.unl.pt/sites/all/themes/javali_theme/images/penduricalho.png"></img></a></p>
        <figcaption>
            aye!!
    </figure>
</div>