Why would my dryer be leaking water out of the bottom?

On both sides (not the front or back) there was puddles of water coming from underneath the dryer. I realized the filter had not been cleaned off in a few loads so it was pretty packed with lint. I have not tested it since then because I am scared something will go wrong. It doesn't seem like moisture from the wet clothes because it puddled up. I'd say about a 1/2 a cup to 3/4 a cup of water total had leaked out from the bottom of the dryer onto the floor. ( area around my washer completely dry)