有一天，天神到森林裡散步，突然聽到空中傳來「吱！吱！吱」的哀叫聲，天神抬頭看到老鷹叨住一隻小老鼠。天神很同情小老鼠，便舉起手輕輕一指，老鷹大叫：「哎呀！」小老鼠就從天上掉下來，天神伸手接住小老鼠，並說：「你以後要小心點，別再被捉住囉！」說完天神繼續散步。
傍晚，天神正要回天上時，看到貓咬著小老鼠，天神再度救小老鼠一命，並對牠說：「你實在太小了，乾脆把你變大一點，就不會被捉。」說完就把老鼠變成貓。變成貓的小老鼠，忘了以前的事，開始欺負一些比牠小的動物。不過，好景不常，幾天後，牠又被一隻兇惡的野狗追，牠邊跑邊叫：「救命呀！天神救救我！」天神又再救牠一命，天神說：「再把你變大一點好了！」這次則變成狗。就這樣每次被更大的動物追趕，天神一次又一次把小老鼠變大，最後，小老鼠變成老虎，從此，牠更是目中無人，到處欺負動物，完全忘記自己以前被欺負的事。
後來，森林裡的動物發現老虎其實是小老鼠變的，大家也開始瞧不起牠，小老鼠便決定：「只要除掉天神，大家就不會瞧不起我了。」當天神來森林看牠時，牠就撲過去一口要咬死天神，天神生氣說：「你這忘恩負義的東西，變回你原來的樣子吧！」老虎馬上變回小老鼠掉到地上，「吱吱吱」夾著尾巴逃走了。
One day, the God of Heaven was taking a walk in the forest. He suddenly heard a shrill call for help. "Squeak! Squeak! Help me!", cried the mouse. An eagle had caught him in its sharp talons. The God felt sorry for the mouse, and pointed his finger at the eagle. "Ouch!", the eagle said, and dropped the mouse. God caught the falling mouse and said, "You should be more careful in future. Try not to get caught again!" Then, God continued his stroll through the woods.
In the evening, just as God was about to return to heaven, he saw that the mouse had been caught by a cat. God rescued the mouse again and told him, "You are so tiny! I shall make you bigger, so that you will not be caught again." He changed the mouse into a cat. The mouse became a cat and soon forgot the past. He started to bully other small animals. One day, he was chased by a fierce dog. As he ran, he shouted for help, "Help! God, help me!" God saved him again and said, "I shall make you even bigger!" This time, the mouse was turned into a dog. Every time the mouse was chased by a larger animal, God made the mouse bigger. Finally, the mouse was turned into a tiger. From then on, the mouse feared nothing. He kept bullying the other animals, and forgot what it felt like being bullied.
Eventually, the animals in the forest learned that the tiger was once a tiny mouse. They lost their respect for him. The mouse who turned into a tiger thought, "If I got rid of God, everyone will respect me." So, when God came to visit him the next day, he tried to bite and kill God. God said angrily, "You, ungrateful creature! Turn back into your original form!" The tiger immediately turned back into a mouse, and squeaked in fear as he ran away.
