That is almost certainly a tussock moth caterpillar. Since there are over 2500 species - and this one is in Malaysia - getting the exact species might be difficult. Also, while many species seem to feed on deciduous tree leaves, this doesn't stop them from feeding on something else that is handy, if they are hungry and outside of their normal feeding area for some reason, I assume.

http://bugguide.net/node/view/378209

http://en.wikipedia.org/wiki/Lymantriida...

My friend in Malaysia found this guy in her thyme plant and posted a picture:

http://instagram.com/p/oR-6bExWWu/

My Google-fu was not up to the task of identifying it myself, but it did give me the words to name the following traits: black pencils, yellow tussocks, gray tufts, white middorsal line/dash, purple (red?) subdorsal spots. Another Yahoo! answer dealt with what kind of caterpillars eat thyme:

https://answers.yahoo.com/question/index?qid=20070215045517AAQfrpU

But the genus the answerer gives is Choleophora, and (to me, an admitted amateur) this almost certainly looks like some kind of tussock moth caterpillar, which would be in Lymantriidae. What gives, caterpillar fans? Do you know what this might be?