You can write a device driver, hook the system service dispatch table (SSDT) and filter out your process when calls to NtQueryInformationProcess are made.
Alternatively, there are several ways of hooking function call in user land. Here is an excellent article that details the process.
If its only for a joke I'd use Jean Azzopardi's suggestion and rename your exe to svchost - no one will notice it at a glance.
I almost forgot, it is also possible to unlink a process from the kernel's list of processes. The process's thread are still run by the kernel but it no longer has any knowledge of the process object and thus won't return the process in any process lists. This is called direct kernel object manipulation (DKOM). Here is an overview of DKOM and the other approaches.