Although "pandeirão" translates to "big pandeiro", it seems to be a very different instrument.

It is a traditional instrument from northern Brazil, here is a translation from a source I'll link below:

"The tambourine is an instrument widely used in Bumba-Meu-Boi folkloric festivals. It resembles a tambourine due to the shape and layout of the leather, but it has larger dimensions and does not have platinum plates - thus, a tambourine cannot produce the sound of 'rattle'.

 [There are] pandeirões [(plural form)] made of wood, with goat leather. The instruments do not have tuners, so they need to be tuned through the heat (fire, stove, oven, sun, etc)".

This instrument is featured as a relationship to a few track on the release "Olho de Peixe" by "Lenine".

Source: http://blog.onjoangoma.com/2010/07/pandeirao.html
Video from source above: https://www.youtube.com/watch?v=smK0mNECJOU
A few pictures by a website called "The Tambour Institute": http://institutotambor.com.br/tradicional/pandeirao/