Burgerpants is a good card if you want to get some money in your pocket. He gives you 9 gold when placed and will give the enemy 3 gold at the end of your turn. Due to his cost to place, he essentially gives 3G to each player.
While it may seem like a huge issue to give your opponent money, you can use Burgerpants in a Bravery Deck in order to have enough money to finish your opponent off.
Keep in mind that if you combine this with Mettaton EX, the enemy will still get their 3 gold from Burgerpants' effect.
Burgerpants himself isn't a good card on his own, with just 2/2, so you can use him as a disposable card. You can for example use him to damage a monster in order to let Asgore finish it off. You can also place Taunt on him with Glad Dummy for some minor extra defence.