Brian is right. There are plenty of fun thing you can do.
When you've made a child laugh, what's the next thing the child says?
"Do it again."
This is an extremely powerful tool. When children are having fun or if they find something amusing, they will do whatever it is again and again and again. It's amazing. Not only will they want you to do it again then, but the next time you see them, they'll ask you, "Do that thing again." (Problem is you have to remember what it was.) In designing lessons plans this can be a key point for game/activity selection and/or creation, as well as presentation. If the students find something amusing they will want to do it over and over again (just ask SEGA.)
The problem is other than tossing them around, tickling them, physically harming yourself, what do they like?
Funny sounds: If you are drilling, try raising your voice 3 octaves at the end and have the students model, sing the word, whisper the word, shout the word, dance to the word, what ever sells.
Funny words: Don't be afraid to make up words or combine words to make non-sense. Children do this and love it. It's one way to learn about morphemes. Tell them you want an elephant-pencil. "An elephant-pencil? No, no a monkey-pencil! No, no. A ROCKET-pencil." "A pocket-pencil? What's that?" Children will jump in and start talking!
Physical comedy: unfortunately this could mean physically harming yourself, but the pros just pretend. I do a lot of street side performance type material that really gets kids laughing and on my side. For example when I meet a child for the first time I may go to shake their hand, miss and run right into them. Then, do it again. And again. And again, until eventually I just deem that there must be something wrong with the childs hand and make him/her shake hands with another child just to verify that his hand actually works and repeat. Small magic tricks hold some value. Then teach the students the same trick and have then try it in English.
As a teacher or at any profession, you can get very bored with the same thing every day. Games and new activities will bring some new life to your classes but you might think about some new things for yourself. Further education as a teacher may bring some new horizons. Beyond new horizons, it might bring you a lot of new ideas.
Build up! Be Positive! Teach hard!
Mark
www.mes-english.com