Millipedes have a long body and many legs. Millipedes have two pairs of legs per (diplo)segment, while centipedes have one pair per segment.
There are 33 species in Singapore1.
The most commonly recognisable type is this red millipede - Trigoniulus corallinus. It has a cylindrical body and curls into a coil when threatened.
The other type that one might encounter are the plated millipedes (Order Polydesmida). Anoplodesmus saussurii, often confused with Harpaphe haydeniana2, is very common in newly developed lands. But it is an introduced species. Another introduced species is Chondromorpha xanthotricha3, which looks like Anoplodesmus saussurii, but is not glossy and has less yellow.
The other plated millipedes can be found in the forests. One such species is Platyrhacus lineatus, the type locality of which is in Singapore4.
Another species is Opisthodolichopus scandens5.
Opisthodolichopus scandens at Lower Peirce ©Eddy Lee
The third type one might find in Singapore is the pill millipede (Subclass Pentazonia). There are able to roll into a ball.
References1. Annotated checklist of the millipedes (Diplopoda) and centipedes (Chilopoda) of Singapore