Unfortunately, most network providers will charge for the use of an MMS and they are very rarely included in any minutes package you may have in your contract. This charge varies from operator to operator, but a good estimate will be approximately 25p per message. It does not cost you anything to receive a multimedia message.
As for where to find them, if you have an iPhone the best place to start looking is the Apple App Store, as there is an application designed specifically to provide animated emoticons for MMS. This app is called ‘Animated Emoticons’ and there is a free version available to download. Simply download this to your iPhone and you will have ready-made emoticons at your fingertips ready to send via MMS or email. As mentioned, the MMS option will charge you at your network rate.
There may be applications available for Android phones, or Samsungs, so it is worth searching either on your phone or online to find out more. Some phones have animated emoticons built in to their text messaging service, but these will only show up properly if you are sending it to the same make of phone.